X6D ONLY Firmware Flashing and Tweaking
Posted 09 February 2011 - 11:25 AM
James at buyadroid - sad to see you go. You are honest, keep your promises and actually provided support. Hopefully this new guy running buyadroid will be as good as you.
Duskol, Derang and Slight User for sending me their nand data.fai files so I could recreate my nand file system. I now have a nand file system again thanks to these three and their selfless effort in backing up their nand data.fai for me.
Boo hiss to everyone who told me how to back it up, but didn't bother to read my request for their nand as I stated over and over that it didn't exist so there was no way to back it up!
This is my first android tablet and it has been a learning experience. However being the humanitarian that I am and taking pity on all the souls out there reading the forums and getting conflicting answers, I have decided to set the record straight regarding the X6D tablet. Soon to be added here will be a very complete document listing everything I have learned about flashing this tablet and hopefully clearing up a lot of the confusion between the X6D and it's X5A predecessors. I have 25 years in the IT field and am a consummate tinkerer. My motto is "Nothing is truly complete until it has been modified". I will soon post pictures here of my tablet and keyboard. The tablet itself is unmodified, but the keyboard, wallet, etc are not quite what the manufacturer had in mind. I took apart the stock keyboard wallet, harvested the keyboard out of it, clips, magnets, etc and then proceeded to make a new wallet out of 1/8" plywood. I have a few minor additions to make and then it will be complete. I borrow power from the mini USB cable which goes to the keyboard. The +5v line feeds into 3 micro switches to turn off the keyboard, keyboard lights and external 2w per channel stereo amplifier hidden under the keyboard. My tablet is nearly as loud as an average laptop and everything is in the wallet/clam shell. All that stuff runs just fine off the internal battery and pulls around 450ma if it's all running at full tilt which is just under the USB current limit. Battery run time is shortened obviously when everything is powered, but that's what the 3 power switches are for. I have some thinner speakers coming that are less than 1/8" thick and I intend to bury them under the keyboard for a much cleaner look and fewer wires going from the bottom (keyboard) to the top (tablet) of the clam shell. As it stands right now I actually get some stereo separation and the new speakers will do even better.
As soon as I get my main computer running again I will get my flashing document out here, but it blew up just last night.
One last thing...
Have you low formatted your x6d or x5a-g and don't have a backup of nand? You can tell if it is missing by going into Settings --> SD Card & Device Storage. Under Nand Memory it should read 2.72gb total space. Also if Mount Nand Memory is not grayed out, select it. You will either see that it mounts nand successfully or you get an alert in the upper left corner of the screen. If you get the alert, you will also notice that Mount Nand Memory will still be lit up. Your nand file system is missing and you need the NAND DATA.FAI file specific to the X6D and X5A-G. Nand data.fai files from other tablets will not work. I tried them from every firmware release I could find and without exception they all failed to install. I even attempted to use a hex editor to edit one so that the byte size of the file and encoded nand size were correct. Without information about what the contents of the file mean, I found it impossible to figure out.
So having said all that...
Ask real nice and I'll send you the nand data.fai file specific to the X5A-G and X6D. Just post your e-mail address. I don't have this file for any other tablets so don't ask. Keep in mind this topic is for the X6D, not all the other tablets out there.
Posted 09 February 2011 - 11:52 AM
Posted 10 February 2011 - 01:09 AM
Are you sure your problem is inside the tablet and that you don't have a bad power supply? All tablets have a charge controller chip in the tablet that monitors battery voltage and current levels. It informs the CPU if the battery is getting low and you then get the message that your battery is low. This chip also controls charging of the LiPo battery. It seems that all tablets have LiPo batteries as they are the thinnest, flattest and highest charge capacity that is reasonably available right now. LiPo batteries do tend to have a limited life span if they are over discharged or not charged correctly to begin with. I haven't specifically looked for replacement batteries, but I suspect that you could take apart an RC battery pack that delivers the correct current rating and voltage and replace your internal batteries. I have considered finding some ultra thin (1/8" thick) LiPo batteries to hide under my keyboard so that the KB, Amp and lights don't suck the tablet battery. I will post my findings. You can buy a replacement power pack at Radio Shack for about $30 (9v, 1500ma) or if you are like me, I scrounge around. I went to the local Habitat for Humanity store and they have bins full of wall bricks. I found 2 9v/1500ma power supplies and soldered on replacement connectors to fit the tablet. I now have 3 power supplies for my tablet. One I leave at my desk at work, another at my bed and another at my desk at home. I paid a dollar for each of them. If you are not sure what the problem is specifically, I would try a replacement power supply first and then replacement batteries and then if you are an excellent solderer, perhaps replace that charge control chip, but the leads are micro small and it would not be hard to damage the tablet logic board with too much heat. I personally own 4 soldering irons and all of them are of course modified by me so they are dual temperature. That second temp setting is useful when you need it, which for me is fairly often. Probably the charge controller is not your problem.
Posted 10 February 2011 - 01:35 AM
Posted 10 February 2011 - 02:47 AM
OK this one is somewhat lame in this modern age of digital displays, but there is use for it too. At work I have an LCD projector that has a video multiplexer attached to it so I can display 1,4 or 8 video inputs simultaneously on one display. I have various monitoring apps that are displayed on a wall sized screen for easy viewing. The multiplexer takes HDMI, VGA, s-video or composite inputs. The problem is that the multiplexer is 30 feet away and HDMI just wont go that far, but composite video will. The X5A, X5A-G and X6D all have composite video capabilities. I suspect that a lot of tablets have the option listed in Settings --> Audio and Video, but there's seemingly no physical connector for it. I found that the the head phone jack is actually a 3 pole connector and that the composite video signal is in the audio jack. A typical 1/8" stereo headphone jack has 3 connection points. The tip is the left channel. The ring right above it is the right channel and the top most section is common or ground. In a 3 pole connector there are 2 rings. The tip and first ring are the same as a typical stereo connector. That top most ring is the composite video. These 3 pole jacks are not too hard to find. I bought a 10 pack on mouser.com, but you can go to just about any audio or cell phone store and find a cable that has the 3 pole 1/8" jack that is an adapter for something. Who cares! You just want the connector and attached wires. I made a 4" long split out adapter that serves me well. It terminates in 3 RCA female connectors which are readily available at most electronics supply stores. The audio channels go to a set of amplified speakers with sub woofer and the composite video goes off to the multiplexer. The common/ground connection goes to all 3 connectors. Viola! I can watch my monitor apps and TV or movies all at the same time.
1/8" 3 pole jack wiring: (Really lousy, but you get the idea!)
/ <---- Left Channel
| | <---- Right Channel
| | <---- Composite Video
| | <---- Common/ground
Posted 10 February 2011 - 04:50 AM
WARNING!!! You may void your warranty doing this and I am not responsible for anything you damage.
*** This is not a firmware issue most likely and reflashing probably wont fix the problem.
*** This is most likely a hardware issue and hopefully a poorly seated connector inside the tablet.
Things you will need:
A large flat surface such as your desk or table
A small phillips screw driver for removing the back cover screws
A towel to lay on the table so you can lay everything on it and not scratch the LCD or have screws rolling away
1. Remove the 4 screws that hold the back cover on or that hold the wallet to the tablet.
2. The back cover is held in by small spring clips in various places that keep the back cover from falling off when the screws are removed. You can get your finger nail into a crack between the metal front and plastic back and slowly ease the back cover off. Make sure that you slowly lift off the back cover evenly all the way around. IE: Don't get a corner loose and then just yank the cover off. You can tear or damage the LCD and touch screen cables making your problem a lot worse. Damage those cables and you might as well buy a new tablet. Ah well! Now you have spare parts! ;-)
3. Those two very thin ribbon cables go to the LCD and touch screen and connect to the logic board that is screwed into the back cover. That logic board is the "brains" of the tablet. It's every function is controlled by that little green circuit board. You will also see 2 flat silver packages attached to the back cover. Those are your batteries. On the ribbon cables, mark them with a permanent marker so you know which way to orient them when you are ready to reassemble the tablet. you can put the cable in the connector upside down, but obviously that wont work.
4. Remove the piece of tape on the wider cable that keeps it in it's connector. This is the LCD cable. On either side of the connectors that hold the LCD and touch screen ribbon cables are tiny black clips that clamp the cables in place. Pull on those clips parallel to the logic board. Don't lift the clips away from the logic board, they are fragile and might break in which case you are possibly not going to get it back together again and you have more spare parts. They will move about 1/16" or less and the cable they hold in place should come out of it's connector with almost zero effort. If you have to pull with any effort to get the cable out of the connector, the clips are not yet released.
5. The LCD screen should now have just a couple of single wires attaching it to the logic board. Be careful to not pull on these other wires, but you should be able to lay the LCD next to the bottom cover.
6. Dip your cotton swab in the alcohol and then rub it on the exposed connections on the end of the ribbon cables. Make sure your cotton swab isn't dripping with alcohol. It only takes a damp swab. You are removing any contaminates and oxidization on the connectors. Wipe the connectors dry.
7. In the reverse order that you removed the cables, reinsert the ribbon cables in the connectors. When you have a cable fully in its connector, push those tiny black clips back in, the cable should now be clamped into its connector. Make sure the cable is fully inserted into the connector and NOT crooked.
8. Once both ribbon cables are reattached, you should be able to lay the LCD/top loosely on top of the back cover. Press the power button and allow the tablet to boot up. Test the LCD and touch functionality. If the connectors were the problem, you should now have full functionality again. If the LCD display is worse than it used to or the touch functions are less functional than before, then you probably have a connector misseated. Shut down and recheck the connections. It is very easy to accidentally pull a cable partly back out as you are pushing in the clips.
9. If all is well, carefully push the back cover back on and reinsert the screws.
Posted 10 February 2011 - 12:02 PM
Disconnecting and reconnecting those cables is not for the clumsy or fat fingered amongst us. GET SOMEONE ELSE TO DO IT FOR YOU!!! The smaller cable is really flexable, short and a royal pain to get back in the connector. If you need to use a pair of tweezers to get the cables back in place, cover the logic board around the connectors with masking tape so you don't accidentally short anything out with the metal tweezers.
I put the large cable in first, because it is easier to work with and long enough to not interfere with maneuvering the smaller cable.
Posted 10 February 2011 - 12:58 PM
My flashing and recovery cookbook:
X6D flashing: (153 firmware)
*Note: Plug in the power adapter so you can't possibly run out of battery before the flash completes.
*Note: do not plug in the USB cable into the tablet until told to.
1. If the flashing process bombs out or hangs up consider installing a fresh copy of Windows XP 32bit on a
blank hard drive. Install ONLY the windows drivers!!! Utilities and other apps may cause flashing to lock up
2. Install the FWDN drivers.
3. On the tablet hold down the Menu button and then hold down the power button keeping both held for 5
seconds. You are now in FWDN mode. The tablet will be at the first android logo screen and appear hung up.
4. Browse to where you have the FWDN program and double click on the FWDN executable.
5. Insert the USB cable in the tablet. In FWDN a window appears briefly saying "Device Init-Start!"
6. Click on the large Nand Data button on the right. In the new window uncheck the "Source Folder" option,
select FAT in the drop down, Type "Nand" in the Partition Label field and then press the ... button and
browse to where you have your firmware files. Click the Save Button and then the long "Create Image" button
at the bottom. After a second or 2 you should see a "Make Fat Image Success" message. Press OK. You will
see your Nand Data.fai listed back it the main FWDN window.
7. In the main FWDN window, click on the "..." button in the upper right corner. Browse to where you have
the rom and img files you want to flash.
8. Double click on the rom file and then click on the "Add File" button. You now see the rom file
listed in FWDN.
9. Click on the "..." button again and this time select "All Files" in the File Type drop down.
10. Double click on the img file and then click on the "Add File" button. You now see the img file
listed in FWDN. You should now see 3 files listed.
11. There is a drop down right above the Start button. If your flashing process doesn't seem to go well with
the "default download" option, try the "Low format" option. Keep in mind that if you don't have your Nand
Data backed up (step 6) you will need to get a copy from someone to restore your Nand Data with. See the "Restoring your Nand Data" section below.
12. Click on the "Start" button. You should see the progress bar advance to completed several times as aspects of the flash process complete. When the whole flash process is finished a green border appears around the progress window and a success message appears.
13. Unplug the USB cable from the tablet and press the reset button. Press power and wait for the tablet to come up like it's fresh from the factory.
*Note as long as you have a valid copy of your Nand data.fai you don't have to back up nand every time you
low format. Just reuse the back up you already have. Do step 9, but select the Nand Data.fai file instead.
To reflash from 157 to whatever:
(The tablet wont stay on unless the power button is held in or the USB cable is plugged in.)
*Note: the 157 Firmware is NOT for the X6D, but rather the X5A-G.
1. Unplug the USB cable. Plug in the power adapter so you can't possibly run out of battery before the flash
2. Browse to where you have the FWDN program and double click on the FWDN executable.
3. Hold down the Menu button and then hold down the power button keeping both held for 5 seconds. You
are now in FWDN mode. You get a the "I Love You" picture. Keep holding down the power button or the
tablet will shut off.
4. Plug in the USB cable, wait for FWDN to recognize the tablet with the "Device Init-Start!" message. You can now let go of the power button and the tablet will stay on and in FWDN mode.
5. Click on the "..." button in the upper right corner. Browse to where you have the rom and img files you want to flash.
6. Double click on the rom file and then click on the "Add File" button. You now see the rom file listed in FWDN.
7. Click on the "..." button again and this time select "All Files" in the File Type drop down.
8. Double click on the img file and then click on the "Add File" button. You now see the img file
listed in FWDN.
9. Click on the "Start" button. You should see the progress bar advance to completed several times
as aspects of the flash process complete. When the whole flash process is finished a green border
appears around the progress window and a success message appears.
10. Unplug the USB cable from the tablet and press the reset button. Press power and wait for the
tablet to come up like it's fresh from the factory. It should now stay on by itself.
Restoring your Nand Data:
You low formatted and you have lost your Nand file system. Don't worry you just need the Nand Data.fai file
specific to your tablet. If you already backed it up, you are golden and just need to restore it. If you don't have it backed up, contact rkenders on slatedroid and I'll email you a copy specific to the X5A-G and X6D tablets. Nand Data.fai files for other tablets will not work.
You can tell if it is missing by going into Settings --> SD Card & Device Storage. Under Nand Memory it
should read 2.72gb total space if Nand is good. If Mount Nand Memory is not grayed out, select it. You will
either see that it mounts nand successfully or you get an alert in the upper left corner of the screen. If you get the alert, you will also notice that Mount Nand Memory will still be lit up. Your nand file system is missing and you need the NAND DATA.FAI file specific to the X6D and X5A-G. You can also tell that the Nand file system is missing because files you have in the Nand folder disappear when you restart the tablet because the Nand folder is a pointer to the Nand Data file system and not a real folder. It's like having a shortcut on your Windows desktop that points to a USB flash drive except the flash drive isn't plugged in.
*Note: These steps will not wipe out your current installed apps or configuration. It will only restore a blank nand file system. Anything that used to be in nand was lost when you low formatted.
1. On the tablet hold down the Menu button and then hold down the power button keeping both held for 5
seconds. You are now in FWDN mode. The tablet will be at the first android logo screen and appear hung up.
2. Browse to where you have the FWDN program and double click on the FWDN executable.
3. Insert the USB cable in the tablet. In FWDN a window appears briefly saying "Device Init-Start!"
4. Select anything listed and press the Delete key to remove them. You don't want to reflash the tablet, just get Nand back.
5. Click on the "..." button and select "All Files" in the File Type drop down.
6. Browse to where you have the Nand Data.fai file stored and double click on it. Click on the "Add File"
button. You now see the Nand Data.fai file listed in FWDN.
*Note: Make sure you aren't in "Low Format" mode or you will wipe everything and need to reflash your
firmware and all your apps and configurations will be erased.
7. Click on the "Start" button. You should see the progress bar advance to complete within a second or two.
When the flash process is finished a green border appears around the progress window and a success message appears.
8. Unplug the USB cable from the tablet and press the reset button. Press power and wait for the
tablet to come up. You should be able to go into Settings --> SD Card & Device Storage and see your Nand
Memory. Mount Nand Memory should be greyed out.
Debricking: Your tablet is totally hosed and wont do anything.
1. Don't panic. Your tablet will very likely live again.
2. Press the reset button and then the power button. If it boots up your good to go. Consider reflashing with the correct firmware for your tablet.
3. Still DOA? Attempt to enter FWDN mode and reflash the tablet.
4. Still have a brick? These steps will possibly void your warranty, but if done right will not harm the tablet and can bring it back from the dead. I'm not responsible if you blow up your tablet!
a. Take the back cover off. Be careful removing the cover so you don't pull on the internal cables. They are somewhat fragile and can be pulled out of the connectors or torn.
b. Plug the tablet into power.
c. Some tablets have a tiny switch on the circuit board used to force the tablet into FWDN mode. Some have the solder contacts, but no switch. Flip the switch and then press the reset button and go to step 4e below. Otherwise look for some very tiny silver contacts that look like this. :' ": The 2 colons on either side are mounting points for the switch and should be avoided. The 2 silver contacts next to each other are the critical ones.
d. Take a very small piece of aluminum foil and tape it down with clear tape over the 2 closer contacts, but NOT over anything else. It is important to NOT cover any other solder contacts or parts with the foil as you can damage the tablet. You may need to press and hold on the foil over the two contacts with your finger. Now press the reset button.
e. Start up FWDN on your computer and attempt to reflash. After the flash completes, flip the switch back or remove the tape and foil, unplug the USB cable and press the reset button. Power up and you should be back in business.
* Note: It is very important to NOT short out anything other than those 2 tiny contacts if you ever expect
your tablet to live again!!! Consider covering the area around those 2 contacts with some masking tape.
* Note: keep the foil pressed down and plug in the USB cable. If you slip off the tape or forget to keep pressing down, just press and hold down on the foil and then press the reset button and you should hear windows acknowledge the tablet and FWDN should detect the tablet.
X6D Android Recovery Mode:
(Reset to Factory State, Flash from your SD card, Wipe out your current cache)
* Note: If the tablet hangs up, goes to a blank screen or otherwise does NOT get to the Recovery menu, you may have a bad flash. Press the reset button and reflash the 153 ROM.
1. Power off the tablet.
2. Hold the Home button button and then hold down the power button keeping both held for 5-10 seconds. You should see the weird racoon logo for a few seconds and then a green android with an exclamation will appear. You are now in Recovery mode.
3. Press the Return button and the "Android system recovery utility" appears.
4. Press Return again and you go back to the Exclamation logo. Press Return once more and the next menu item is selected. Repeat this sequence until you have selected the option desired.
5. Press the menu button to execute the option.
Additional comments about the X6D:
* The 157 ROM does NOT work on the X6D properly. It is meant for the X5A-G. DO NOT INSTALL IT ON AN
X6D!!! You probably will have to hold in the power button or leave it plugged into USB to get the tablet to stay on and booted. you will probably also see the "I Love You" screen during the boot process. You will have to reflash the 153 ROM which is the latest for the X6D.
* To determine what tablet you have open Settings --> About Device. Look at the Model Number. Install the firmware appropriate to your tablet. Firmware for other models might work somewhat, but with issues.
* Holding Return/Power or Return/Home/Power does nothing. Press reset to boot normally.
* Holding Menu/Power or Menu/Home/Power or Menu/Home/Return/Power puts the tablet in FWDN mode. Press
reset to restart normally.
* Pressing on the screen and holding the power button does nothing.
* Safe Mode: Press the Power button and wait for the "ANDROID" logo to appear after the weird raccoon. Press and hold the Menu button until the android desktop comes up. You should see "Safe Mode" in the lower left corner. Safe Mode keeps background apps and services from running and is primarily for trouble shooting purposes.
Posted 11 February 2011 - 05:44 AM
Where do I find parts for stuff like this? The Amp was bought new at Walmart for $20. The USB tablet keyboard I found on ebay for $20. Everything else is wires and connectors scrounged out of various electronic devices. Everyone has an old VHS or super 8 video camera lying around or an old VCR. These things are a free treasure trove of small otherwise impossible to find connectors and other parts. The LED's that light up the keyboard when the lights are out are surface mount LED's scrounged from an LED light bulb I bought new. I looked at mouser and else where for 3 volt high intensity SMT LED's and it cost as much to buy 5 or 10 of them as it did to buy a light bulb at Walmart that contained 27 of them. Now I have lots of spares! You can find furniture grade 1/8" plywood in drawer bottoms of an old dresser or on back of the dresser. Mostly I try to scrounge stuff. I needed some 1/16" thick plywood and found that at Hobby Lobby.
Posted 11 February 2011 - 08:07 AM
Posted 11 February 2011 - 05:28 PM
***If you can't solder very well DON'T DO THE BELOW!!!
***If you don't understand basic electronics, DO NOT PROCEED!!!
***Do NOT use a soldering gun, plumbers torch or a wood burning iron you will burn to a crisp everything you touch with it.
***Do NOT use plumbers solder! Get the thinnest 60/40 solder you can find. I use .032"/.8mm or thinner solder.
***A 15 to 25 watt soldering iron is perfect. Anywhere you find soldering irons you will find electrical solder.
This modification requires 2 pairs of 3.7 volt LiPo batteries. You need to find a second set of batteries identical to the ones already in your tablet. An individual LiPo cell regardless of it's current rating is 3.7 volts requiring 2 of them in series to get 7.4 volts to run the tablet. You have to run 4 cells in 2 parallel sets to increase battery run time. The end result being that if you originally had 2400mah, you now have 4800mah but still at 7.4 volts. There is a problem to overcome. LiPo's are very particular about being charged at their rated amperage and voltage. The charging circuit in the tablet is designed to deliver the current requirements for a single battery set. So if that is 2400mah, 2 battery sets in parallel will require 4800mah to charge both sets to 2400mah each. When you put 2 sets of batteries in parallel you are effectively delivering half the charging current to each set. That means the first battery set charges to 1200mah and so does the second battery set. Effectively you might get a tiny bit more run time, but not enough to make your efforts worth while. Also, the charging circuit may not be able to handle the current draw that 2 battery sets in parallel would put on it and cause it to burn out. Kiss one nice tablet good bye! What you need to do is put your two battery sets in parallel, but keep the charging circuit isolated from the batteries. The red battery wires need to be soldered to the anode end of a diode that is capable of handling 5 amps or more and then solder the cathode end to the solder pad that originally was for the red wire of the battery. The effective result is that current can flow out of the batteries and into the tablet, but the charging circuit can't flow current back into the batteries. That is to say diodes are "one way" devices. Current only flows in one direction through them. The electronic schematic symbol looks sort of like this:
Current flows in here (anode) ---|>|--- and out of here (cathode), but not the other way
Real diodes are generally cylindrical with one end having a white band around it indicating the cathode.
The easy, less elegant and more dangerous way...
You will no longer use the included power supply to charge the batteries. The tablet will run just fine from the wall brick or batteries, but the batteries wont charge from the wall brick. The trouble is you need double the current to charge the double battery pack properly. The charging electronics and wall brick were not designed to deliver almost 5 amps! They will probably overheat and burn up if you try. What you need is an R/C LiPo balance charger. You can pick up a 1 to 6 cell programmable charger on ebay for around $40. You will need one that can charge at 7.4v and 4800mah as in the example or whatever double of your single battery pack is. This will allow you to charge the battery pack as if it were a single monster pack. Using this method solder a power connector to the plus and minus leads of the whole battery pack, but on the battery side of the diode. Modify the case in some fashion so you can access the power connector externally with the tablet assembled. Matching male and female power connectors can be picked up at most electronic supply stores for less than $4. You will then charge your internal mega battery pack off the external R/C LiPo charger set to 7.4 volts and 4800 mah. Be careful to NEVER set the charger to more than 7.4 volts and your required current as your tablet will also get the extra voltage and will possibly get fried and the batteries may explode.
The more difficult, more elegent and safe way...
If you want to get sophisticated and charge those battery packs with the internal charging electronics without overloading everything here is how. One battery will always be charging if the wall brick is plugged in. Your job will be to notice when that battery is charged and then flip the switch to charge the other battery. Unplugged the tablet will drain equally from either battery pack. To me this is fairly elegant, nearly automatic and easy to do.
1 DPDT or Dual Pole, Dual Throw (2 positions, 6 legs in 2 rows) slide switch.
1 15 volt 1000uf electrolytic or tantalum capacitor
Hot glue gun and glue sticks
Heat shrink tubing
15 to 25 watt soldering iron and solder
2 different colored stranded wires, black and red is best
* If you absolutely can't find the electronic parts and a small DPDT slide switch, mouser.com carries anything electronic you could need.
What is this stuff for anyway?:
The switch will need to be small enough to go inside the tablet and accessed with the tablet fully assembled. A small power switch scrounged from a toy will probably work well. AM/FM ONLY radios that turn off with the volume knob have small DPDT switches in them to select AM or FM. A lot of cheap R/C stuff use them too. Modify the case and mount the switch where you can get at it easily. Don't worry that the switch contacts aren't rated at 2.4 or 4.8 amps or better. 1 amp is plenty. The heavy current load comes when you unplug the tablet and all that current flows through the diodes, not the switch contacts.
The diodes will isolate the charging circuit from the 2 sets of batteries so that it can't "see" both battery packs at the same time when charging. Find a 9 or 12 volt wall brick you don't care about, take it apart and you will probably find 2 or 4 diodes inside that will work well.
The capacitor smooths out the switch transitions. Electrolytic caps are larger, cheaper and easier to obtain than tantalum caps, but sensitive to prolonged heat exposure. Don't worry your tablet doesn't get that warm inside. Personally I would go with the tantalum capacitor because of size, they are super reliable and hardly ever fail. If you can't find tantalum's, electrolytic caps will work fine too. You may find that a 1000uf electrolytic capacitor wont fit in the limited space inside the tablet. 2 470uf, 15 volt caps are much smaller and in parallel effectively equal a 1000uf capacitor. 940uf is close enough for our purposes. 3 330uf caps in parallel equals 990uf. A 470uf, 330uf and 2 100uf caps all in parallel equals 1000uf. It doesn't really matter what you have to use to get close. Just make sure they are all electrolytic or all tantalum and that the voltage ratings are all 15 volts or higher. You just solder all the negative leads together and all the positive leads together to make them parallel. Old car radios have an abundance of compact electrolytic capacitors in them. You may find what you need in that wall brick you just took apart too.
Tips, conventions and general suggestions:
*The positive (red wire) solder pad on the logic board I will refer to as BC for Battery/Charge. The negative (black wire) I will refer to as ground.
* Depending on how much room you have and how small your parts are most everything can be soldered right to the switch.
* The capacitor is polarized meaning you have to hook up plus to plus and minus to minus. Hooked up backwards will damage the capacitor.
* Red wires always mean positive, black always means negative.
* Any exposed solder connection that can move or that can possibly touch something metal is a potential short circuit. Use short pieces of heat shrink tubing to cover those connections. Use the smallest diameter that will fit over the connection. Heated with a lighter or soldering iron will make the tubing shrink. A small piece of electrical tape works well for things heat shrink tube wont go around.
* Cut your wires a little too long so you have some wiggle room. If you need 3 inches, cut your wire 3.5 inches long.
* Barely strip the insulation off the ends of the wires. Tin all your exposed wire ends before you attach them to anything. It makes soldering them in place a lot easier. If an exposed end is more than 1/8" long, cut it back. Short exposed wire ends are best.
* Cover the exposed ends of the red battery wires with tape so you don't short them on something accidentally.
Let's get started building the battery hack:
1. Unsolder the red wire from the existing battery at the logic board (BC). Shorten the exposed wire end if needed and then cover it with tape so it can't short against anything. The LiPo battery may be rated at 2400ma, but that doesn't mean it can't discharge for a very short time at a much higher amperage!
2. Connect the capacitor to the positive (BC) and negative (ground) solder pads on the logic board. Use lengths of red and black wire to locate the capacitor where it will fit. Red is positive, black is negative. Be sure to get the polarity right. Put heat shrink tubing over the solder connections and bare metal legs on the capacitor.
3. Cut 2 lengths of red wire long enough to get from BC to where the switch will be mounted, taking into account that you may need to route the wires around things plus a little extra. Keep in mind that the batteries need to fit inside the case too so don't put the switch where it will interfere with them. Solder one end of each red wire to BC.
4. Solder the black wire from each 7.4 volt battery pack to the ground pad on the logic board. You should have 2 black wires and the minus side of the capacitor soldered here.
5. Arrange the batteries so they fit inside the available space and attach them to the lid or underside of the LCD with a little hot glue. If you use a lot of glue and later discover you need to shift things around a little you will never get the batteries loose again without damaging something.
6. Label your original battery pack with B1 and the new one with B2. B1+ means the red wire on the original battery or it's positive connection. B2+ plus means the same thing but for the second battery pack.
7. Solder the diodes directly to the switch terminals as shown in the diagram.
8. Solder B1+ and B2+ to their appropriate switch terminals.
9. Check everything to make sure you made no mistakes or solder bridges. So far you couldn't really hurt much if you made a mistake.
10. Solder the red wires from BC to their appropriate switch terminals.
11. Check again for solder bridges, bad solder connections and miswired parts.
12. You should be able to plug in power, boot up and test your work.
13. Leave the switch in whatever position it is currently in and let the battery fully charge.
14. Flip the switch to it's other position and let that battery fully charge.
15. You should be able to unplug power and get double the run time you had on a single battery pack. It doesn't matter which position the switch is in to run off battery power. The tablet will pull equally from both battery packs. Repeat step 13 and 14 to recharge.
The only other thing to do is totally automate the dual charging process. There would have to be a small battery charge level monitoring circuit that switched the charging circuit back and forth between the batteries depending on which one was partially discharged. I may have to explore this further. I have a couple of LiPo battery monitoring devices for R/C that could be pressed into service. Better yet a simple comparator circuit that controls a couple of SCR's . The comparitor enables the SCR to which ever battery has the lowest voltage, but can't enable both SCR's at the same time. An SCR is very similar to a diode. Current flows only one way through them, but they have 3 connections rather than 2. In, out and control or anode, cathode and gate. Apply a control voltage to the gate and the SCR starts acting like a diode. Take the control voltage away and it's like you turned off the lights or an open circuit. They get used in all sorts of places to turn things on or off, sometimes really fast too. Dimmer switches or variable speed drills use them. When you barely pull the trigger on your drill and it turns really slow, you hear it making a whining sound. What you are hearing is the drill motor turning on and off really fast. Pull the trigger a little more and the pitch goes higher as the motor turns on and off even faster. Finally the whining noise gets above our hearing range or is drowned out by the drill noises, but the motor is still very quickly turning on and off until the trigger is pulled all the way in. Dimmers work the same way. You want a dimly lit room, turn the dimmer down. Really you are turning the light bulb on and off more slowly and so it glows let brightly. If you listen closely, you can hear the bulb making a noise, but it's very quiet since there are no moving parts. All that stuff and more is done with SCR's. Since they have no moving parts or contacts to wear out, they will last forever as long as you stay within their voltage and current limits.
Posted 12 February 2011 - 09:38 AM
I maybe didn't understand well but how do you make 2 sets of batteries fit inside?There is not enough space as I remember.
I dont have a X6D but that should be pretty much the same inside as the X5G-G
Thank you very much for your details, I'll try the video composite hack.
Edit: I made it!
I took a old FM transmiter for Ipod and use the jack that has 3 rings,all work perfect just one thing ; the screen on TV dont give me the whole screen on the tablet missing 1/4" each side include up and down.Is there a solution for that?
I now can watch movies on regular TV with no HDMI, YEAP................
This is fantastic as I installed the NTFS support from this thread http://www.slatedroi...?topic=14081.0 and I now have a portable 320gb external USB drive I can use to see more movie on the tablet or any TV
Posted 13 February 2011 - 12:06 AM
Posted 13 February 2011 - 11:31 AM
check out my screen flicker and touch pad post. There are 2 ribbon cables that connect the LCD to the logic board screwed to the back cover. The little one is the touch pad cable. You will have to pull both cables out to do it, but the connector is the problem most likely. The tablet face is covered by a pressure sensitive grid. On resistive screens like the X6D has when you press on a spot on the LCD you are lowering the resistance of that area of the screen. The electronics look for reduced resistance areas and interpret that as a you touching the screen. The buttons work the same way, but rather than a grid, it's a little circle. The grid signals are encoded into a data stream, but the buttons are single data lines in the cable. Go figure! So cleaning the connector end of the ribbon cable should take care of the problem. If it doesn't, you pretty much are screwed. This is almost always a hard ware issue so I have little confidence that a reflash will resolve anything ,you could try it.
By the way...that touch pad cable is a bitch to get back in again! I strongly suggest you use masking tape to cover everything around the connector so you don't short anything out. Use tweezers to hold the cable in place and then push the clips in. Make sure the cable is all the way into the connector and straight. Once you have the connector locked in, give it a slight tug to make sure it's in there. If you barely got it seated, it will pull back out. If you put the cables in upside down nothing will work...no video, no touch screen, but you didn't hurt anything either. If you get cable in a little crooked you will possibly get some functionality, but again you probably didn't hurt anything. Just shut down and reseat the correct cable. This is an operation where you wish you had 3 hands, but I was able to get mine apart, cleaned and back together in about 15-20 minutes by myself.
Posted 13 February 2011 - 03:03 PM
Posted 13 February 2011 - 03:05 PM
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