Since I've spent 2 days and nights on trying to recovery my Dropad A8i, I would like to share with my experiences.
(Almost all the knowledge about this specific topic comes from this forum, and credits go to many. I've read all the posts on that matter,
and everyone who at least tried any method posted somewhere here have his own contribution)
I TAKE NO RESPONSIBILITY FOR YOUR ACTIONS AND USE OF THIS GUIDE!
- internal microsd card,
- external microsd card,
- tablet with NAND.
(My Dropad A8 have on-board NAND memory and dual sdcard slots (internal & external), so I cant be sure if this guide will work for NAND only phones.)
* HP USB Disk Storage Format Tool - http://files.extreme.../file.php?f=197
* HDD LLF Low Level Format Tool - http://hddguru.com/s...el-Format-Tool/
* ALMOST ALL ROMS - http://www.flanesi.i...e-disponibili/#
* WinImage - http://www.winimage.com/download.htm
I. UPGRADING WITHOUT REMOVING BACKPANEL
0. (optional: You can skip this step if You can do step 1. with no errors)
- format you external sd with "HDD LLF Low Level Format Tool": this will delete all partitions on Your sd card, and format it to RAW.
1. Format external sd_card with "HP USB Disk Storage Format Tool":
- set Your device, filesystem: FAT32, uncheck any other option, start formating (this will take a while, like > 30 min for 8gb)
2. Open WinImage -> Disk -> Restore Virtual Hard Disk image on physical drive... -> select Your sd_card -> select rom image: either with .mm extension or .vhd extension.
(Images are located in main dir of rom; I've found only two different files: "INand_mm_sd_mbr.vhd", and "u-boot-sd.bin.mid703v3.mm" - both worked for me)
- if You'll get errors like "Can't write to drive.. etc", remount sdcard reader to other usb slot and then try again. If that won't help, restart the system and try again.
3. After restoring image, unplug & plug sdcard reader, windows should automatically recognize it and prompt to format; don't do that, instead
open Control Panel->Administrative Tools->Computer Management->Storage->Disk Management.
- Select largest partition (ie. 2.93 GB) - if You are using > 4 GB card then there probably will be some unallocated space; leave that as it is.
- format selected partition to FAT32 (I think it worked for me with quick formating, but don't beat me if I'm wrong)
(this step is important, because we need PROPERLY FORMATTED partition to be recognized by device - note that this is the last format on sd card;
You could probably skip step 1 and 2, but I haven't tried that)
4. Copy one roms to previously formatted partition.
- try to use rom with erasing NAND in script - which is probably crucial for hard bricked tablets, for others default ROM should work fine)
- all Prox32 roms I've tested had this procedure
(You can check if rom have this option, by viewing utscript.sh and searching line "erasing NAND" or sth. like that in Prox32 roms, however other roms may have this instruction and no such text, as it only output for lcd)
(in my case Evolution 2 R6, M7_20111010, HerotabC8_V2.2_2011_03_01, Paradise Version 2.1 roms worked fine)
5*. Open Your external sd card, then remove file utscript_sd.
6*. Still in external sd card, copy file utscript.sh and paste it to get 2 instances of the same file.
7*. Rename utstcript (copy).sh to "utscript_sd".
8. Safely remove sdcard from pc, then plug it to external sd reader in your tablet.
9. Press and hold button "M", and while holding it, press and hold "Power" button. Hold them for few seconds -> You tablet should boot in upgrade mode
* Don't follow this steps if You don't have NAND - if You'll do it, You just probably will have to repeat whole process again, as it will install system on both internal and external sd card.
II. UPGRADING WITH BACKPANEL REMOVAL = HARD BRICK REVIVAL GUIDE
This method was posted before somewhere on the forum, though there was no picture picture.
IT SHOULD REVIVE ANY BRICKED TABLET - method uses built-in function of dropad/haipad/herotab and a little hack which makes NAND 'invisible' for Samsung MCU,
which causes MCU to look for boot files / upgrade files in other drives - sd cards. Using healthy tablet and proper sd cards should help in most cases, and by
proper sd cards I mean ones that previously worked with tablet, or similiar, with proprely prepared data (or no data: on internal SD)
1. follow method I(0- for preparing external sdcard, but don't plug it in to Your tablet
2. Remove backpanel
3. Unplug internal sdcard
4. Follow method I.0 for internal sdcard
5. plug formatted internal card to internal slot, and external card to external sd slot.
6. short pin 7&8 on Your NAND (see attached image - I've used drawing pin for this task.) - You must be really careful on that, check twice if you are connecting correct pins
do it with hard power switch set to off (slider on the right side of tablet). When You are sure, switch it to "ON".
7. While shorting pins, follow step I.9
8. When Your tablet enter "upgrade mode" release shorted pins.
My tablet was bricked 2 times - first time I was able to restore f/w with method I.
Second method revived my tablet from no booting (including I'st method), no screen backlight, no usb-seen state to fully working with genesis 3.1.1 rom 1.2 GHz (btw. this ROM bricked my tablet in both cases)
I'm not sure if restoring virtual image is actually required, but I haven't tried without using it. However it can do sth with MBR.
Theoretically, restoring image on sd card destroys previous filetype, because it removes all partitions and create other ones, so if You are restoring image, You can try without pre-formating.
In my opinion, whole thing is to force tablet to look for upgrade files on external sd, and make sdcard recognizable for tablet.
PS Also tried this method (shorting I/O pins but it's not working or I did sth wrong.
Hope there never be a reason for anybody to use this guide
Edited by rhaziell, 17 January 2012 - 05:37 PM.