Asus Transformer T100TAF bios dump help! (Partially repaired) - Page 1
Forum section: electronics / repair

author: poot36
author_rank: Frequent Contributor
timestamp: May 10, 2016, 04:05:28 am
content: I have a Asus T100TAF tablet that runs windows 8 on my bench from a customer that flashed the wrong bios to it. I am wondering if someone has a bios dump for it? I have managed to dump (perhaps incorrectly) the corrupted bios from the unit. I have tired to follow the guide here:https://hackaday.io/project/8751-asus-t100ta-resurrectionand have used the bios file for the T100TAF instead of the guides T100TA model. I am using the rayer spi parallel port interface for communicating with the chip modified with a level converter to get it to work at 1.8V Link:http://rayer.g6.cz/elektro/spipgm.htm.When the tablet first came in the white camera light would not stop blinking and it would not show the Asus boot logo. After I tried the new bios the camera light does not blink and it still does not power on. It now however will blink the orange charging light with just the battery plugged in with 1 long blink per second twice and then a 3rd quick blink. This even happens with a empty bios chip. Is it something to do with the charging circuit being controlled by the bios that is now not working? I have even tried re-flashing the bad bios flash back to the tablet but no change in behaviour. The battery has 4.0V or so in it.

author: Rasz
author_rank: Super Contributor
timestamp: May 10, 2016, 07:26:22 am
content: 1 customer might be lying2 have you verified your flash?3 new bioses require more than bios.bin in the flash, UEFI variables, config junk etcbest to flast full dump from another working unit

author: poot36
author_rank: Frequent Contributor
timestamp: May 11, 2016, 01:41:15 am
content: 1.The customer was trying to flash a custom rom for unlocking all the bios features of the tablet. They are the security paranoid type of customer and was wanting to use the tablet to view the deep web. How a bios would help with that I have no clue.2. I used UEFITool for windows (https://github.com/LongSoft/UEFITool) to load up my dumped flash and it did accept it but did show some errors about blank space in the rom. It also mentioned the bios starting at 0x300000 (verified herehttps://www.bios-mods.com/forum/Thread-NEED-CLEAN-IMAGE-DUMP-FOR-ASUS-T100TAF) verses the T100TAs 0x400000 (https://hackaday.io/post/28985). When I try to load up the bios from the hackaday site with the program it does not even load it and shows a error message.3. Hopefully I can get one.I have found out that the tablet is now not charging even with the dumped bios image placed back on the tablet. Is it possible that the programmer has damaged something else on the tablet? The only major things that I did differently from the schematic was first try it with just the 150 ohm resistors and no pullup diodes and when that did not work I did build the transistor buffered version (but kept the resistors at 150 ohm) and added pulldown diodes to clamp the voltages on the input lines to around 2V or so which allowed me to read the bios chip. Is it possible that the original voltages from the parallel port could have damaged some other components (besides the bios chip)? Or would the clamp diodes in the other chips have protected them from the current limited 5V? If I remember correctly I did measure around 2.3V after the resistors on this non diode clamped version.

author: Rasz
author_rank: Super Contributor
timestamp: May 11, 2016, 06:04:08 am
content: I meant did you verify flash actually holds what you programmed, did you read it back and was it ok?

author: poot36
author_rank: Frequent Contributor
timestamp: May 12, 2016, 01:03:04 am
content: Sorry for the misunderstanding. Yes the bios chip does hold its code correctly. I verified using Notepad++'s compare function.

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: May 13, 2016, 05:01:43 am
content: Did you try recovering from a USB flash drive .http://www.transformerforums.com/forum/asus-transformer-book-t100-faqs-guides-tips/47252-asus-t100ta-bios-recovery.htmlhttps://www.asus.com/support/Download/3/580/0/7/7ybWBe9uCDhBbptO/41/http://www.win-raid.com/t624f39-Intel-Trusted-Execution-Engine-Drivers-Firmware-amp-System-Tools.html

author: poot36
author_rank: Frequent Contributor
timestamp: May 13, 2016, 05:59:05 am
content: I did try the USB recovery option before even trying the manual bios dumping and flashing. I don't know if it just did not like the flash drive or that procedure does not work on my model (mine is a TAF not a TA) but I had no luck with the USB recovery. My biggest concern right now is that I cannot seem to get the tablet back to what it was originally doing (blinking wight camera light). Now I have a orange charging light that flashes once per second twice and then a longer the 1 second pause and then the cycle begins again! Have I fried something on the board or is the battery needing calibration or special software to properly charge and run?

author: poot36
author_rank: Frequent Contributor
timestamp: July 18, 2016, 06:33:56 am
content: Well I finally managed to find a bios dump on a website. I have successfully programed the bios chip and then found another fault, a resistor that pulls up one of the data lines out of the battery was mostly destroyed (just the end caps were still there). I have no clue as to what value this resistor should be but as it is on what I think are I2C lines I am going to guess around 20K? or so. Right now I have just replaced it with a blob of solder and the tablet now turnes on. Not sure if it is charging though. I don't have high hopes for finding a replacement resistor much less soldering one back into place (i think it is a 0402 size but it could be smaller though). Got any idea what the value should be? On the other line out of the battery there are two resistors attached to it and one of them measures in circuit 100?s and the other 17K?s. The connection with the missing resistor only has one resistor connected to it though.

author: poot36
author_rank: Frequent Contributor
timestamp: July 24, 2016, 06:28:35 am
content: Ok after trying to get the recovery partition loading I managed to rebrick it (blinking wight camera light) so I reflashed it again and then loaded win 10 x86 on it. The battery does fully charge but I am having trouble with getting the wifi working. Device manager says the driver is up to date but also has a device cannot start code 10 error. I have tried a bunch of drivers and no change. Is it because this bios is a copy from another tablet so the serial numbers don't match and this is messing up the wifi chip somehow? Got any ideas of how to fix this?

author: amyk
author_rank: Super Contributor
timestamp: July 24, 2016, 02:40:07 pm
content: What WiFi chipset does it use?

author: Chalcogenide
author_rank: Regular Contributor
timestamp: July 24, 2016, 04:17:19 pm
content: I had a similar issue with an HP Pavilion 10 X2 that had a "Broadcom 802.11abgn Wireless SDIO adapter" that consistently showed Error 10 after waking up from standby. I managed to fix it by using drivers for a Toshiba tablethttp://support.toshiba.com/support/viewContentDetail?contentId=4008154I recently formatted it and installed Windows 10, and the drivers that were installed automatically work just fine. Also you should download the latest drivers for the chipset/SoC

author: poot36
author_rank: Frequent Contributor
timestamp: July 26, 2016, 03:29:45 am
content: You are correct that it is the "Broadcom 802.11abgn Wireless SDIO adapter" that is causing the error code 10. I am also getting under system devices two "bcmfn2 Device" errors indicating that they are waiting for another device to start code 51. I presume this is the wireless card that they are waiting for. I have updated the chipset drivers and used the Toshiba driver for the wireless and no change. Got any other ideas? Is there a UEFI x86 Linux live distro that I could try to see if the wireless card works under that os to eliminate driver or other software issues?

author: Chalcogenide
author_rank: Regular Contributor
timestamp: July 30, 2016, 06:46:12 am
content: Definitely try with the live linux. If it works there, we know it's a software issue.Did you try a hard reboot? Sometimes things get stuck in a fancy state and don't work correctly. Apart from that, I have no other clue. Maybe just disable and re-enable all the devices that are acting up from device manager?BTW, the driver I am currently running on Windows 10 is version 5.93.102.10. I also disabled active standby because I don't really need it, together with the fast boot option because with the eMMC the difference in boot time is minimal and it's an other thing that can fuck up with device initialization, IMHO.

author: poot36
author_rank: Frequent Contributor
timestamp: July 30, 2016, 06:06:08 pm
content: I have found what is called a magic stick 1.6 for the TA version of the tablet and while it boots Linux I get no wireless device showing. I assume that is because there is differences between the TA and TAF versions of this tablet. How would I go about installing a correct driver under Linux? I have never done this before. The wireless never worked and this is a fresh install. I don't think that the problem is standby related.

author: Chalcogenide
author_rank: Regular Contributor
timestamp: July 31, 2016, 10:01:55 am
content: I don't think you need any special linux distribution. I would just go for the latest ubuntu version, even if it is 64 bit, and see if when it boots it detects a wireless device. I can do that no problem on my HP tablet, which has virtually the same hardware, and UEFI as well. This is not an android tablet with locked bootloader, you can run whatever x86/amd64 linux distribution you want.Just download it to a USB flash drive using unetbootin or similar, and delect the boot media from windows (keep shift pressed and reboot - you will enter a menu, select troubleshoot, advanced and then boot from the correct drive).

author: poot36
author_rank: Frequent Contributor
timestamp: August 01, 2016, 02:28:11 am
content: I do know that the bios on my device only supports booting off 32 bit UEFI media and I don't think that the generic Ubuntu install/live disk supports that. If you can link me to a live bootable disk that is 32 bit and UEFI compatible please let me know. Otherwise I think I am stuck trying to get the driver in the Magic Stick version 1.6 live version installed which I have no clue how to do.

author: poot36
author_rank: Frequent Contributor
timestamp: August 01, 2016, 06:31:40 pm
content: I have just realised that when I turn on network boot on in this bios I don't get the network card as a boot option. Not sure if this is only for USB network cards or the internal wireless. Can you do network boot off a wireless card?

author: Chalcogenide
author_rank: Regular Contributor
timestamp: August 04, 2016, 09:14:26 pm
content: As far as the network boot option, I don't think I have ever seen a device capable of booting off a wireless network, so I wouldn't be concerned atall.Did you try to follow this guide?https://sturmflut.github.io/linux/ubuntu/2015/02/04/installing-ubuntu-on-baytrail-tablets-version-2/It shows how to install (so also just boot) linux on a 32 bit UEFI.

author: poot36
author_rank: Frequent Contributor
timestamp: August 04, 2016, 10:46:16 pm
content: You have a point about using wireless to boot. I think the only computers that can do it are the newer Macs. I did manage to install the Ubuntu from the Magic Stick and take it from 15.04 to 15.10. I still do not have the wireless working though and also managed to nuke my windows 10 install. Oh well. I am going to try and take it to 16.04 if possible.

author: poot36
author_rank: Frequent Contributor
timestamp: August 10, 2016, 03:24:46 am
content: Well I managed to get Android 5.1 rc1 installed and booting on my device and the wireless works! Now I know it most likely is a software issue but could be a bios issue as well as I found references in the original corrupt bios to windows locations for wifi drivers in plain text as well as windows certificates websites and references to canonical (Linux) and Android ADB! This is turning out to be a very interesting tablet now! I just need to figure out how to remove rooted part of the Android install and my game should run.

author: flashcoder
author_rank: Newbie
timestamp: September 25, 2016, 08:51:30 am
content: Hi, I have this T100TAF tablet too and it does not boot. It charges the battery fine. It turns on, blinks the power button then after like 3 to 5 seconds I get the solid camera light and thats it, it freezes right there nothing more happens, no back light no image (tried to see with bright flashlight). If I hold the power button longer and it will restart. I tried that BIOS recovery trick where you hold the button under volume buttons simultaneously with power and keep holding it till camera lights up but nothing happens.I would like to try to re-flash it but I need the dump file. I have searched and found this thread, maybe you could share the dump you managed to find?Thanks,Neal

author: poot36
author_rank: Frequent Contributor
timestamp: September 25, 2016, 10:39:53 pm
content: I don't think your problem is caused by a bad bios. I would try unplugging the internal battery for 1 hour and then re-connect it and see what happens. If it does not work then you will most likely need to flash the bios. Here is where I got the bios:https://vinafix.vn/threads/asus-transformer-book-t100taf.19296/you will have to log in to download it. I do not recommend this version though as you will lose your Windows license key in the bios as well as have the WiFi not working correctly if at all. What apparently happens in this bios is the settings that you make in the bios setup are stored on the bios chip and you can't revert to bios defaults because it is permanently programed into the chip and removing power wont fix it. If someone can figure out where these settings are stored in this bios I suspect that a lot of these tablets could be fixed and still retain the Windows license key and WiFi functionality.