Bricked trying BIOS update

[Richard Russell]

my tab just bricked also after “successfully” flashing the bios through the windows utility included in the software… I, too, am looking for options. A search through the Chuwi forums shows a long history of tablets failing through the bios and users unable to recover them.

It’s 6:15pm on Friday in China too, so we won’t be seeing any immediate help from Chuwi

[Ben]

I successfully flashed it by booting the usb containing the files by pressing f7 during boot up.

 

[Bill Christiansen]

Ben wrote:

I successfully flashed it by booting the usb containing the files by pressing f7 during boot up.

That’s what I was trying to do but it went straight to usb so didn’t give me a chance to access the boot menu.

When you did it did you get any on screen GUI? My screen just remained black.

[winston smith]

You need to flash it gaint with an usb programmer and a clip.

[Richard Russell]

winston smith wrote:

You need to flash it gaint with an usb programmer and a clip.

Thanks for the suggestion, I’ve never done that before but I’m not afraid to open this brick up at this point. I know hardware can vary based on manufacturer, but are usb programmer and clips universal, and is there a particular tutorial online that you would recommend I follow?

[Bill Christiansen]

I’ve ordered usb programmer and clip mentioned in this thread: http://techtablets.com/forum/topic/dual-os-version-announced/page/2/#post-27702

Will give it a go in a few weeks when I’ve got it.

[Ben]

the flashing process will be very obvious. lines of scripts will appear and you will be given 5 seconds to proceed or to abort.

Ohkis wrote a tutorial in the pinned discussion up at the top of the forum. Go have a look

 

[Bill Christiansen]

Yes, that was the procedure I used but didn’t see any messages on the screen just a lot of usb activity. I probably didn’t wait long enough and force powered it off so now the BIOS is gone and can’t boot anything. Hopefully can be resurrected with a usb programmer.

[Richard Russell]

I’ve ordered a USB programmer and clip from Amazon, will be delivered tomorrow 5/22 so I’ll let you know if it works

[Bill Christiansen]

good luck, take your time and don’t rush it. You might need access to an older PC or laptop as I don’t think Win 10 is supported by the flash program.

[Richard Russell]

well I was able to flash and verify the new bios successfully (according to the program), but like the best laid plans, I soldered the power wires back on and tested it and I got no response from the system at all, not even the USB power that it had before.

Good luck with yours

[Bill Christiansen]

I’m sorry to hear that. Were you able to check if the battery had any voltage left? Mine had the same symptom of sign of usb power on the first day I lost the BIOS but by the next day nothing so I think it may have been continuing to drain the battery after I thought I’d powered off.

[OlliFromGermany]

I had the same problem. No sign of life and the battery at 3.1v – fully discharged. (at 3.1v stops the pmic – axp288c)

First of all: the BIOS Chip is a Winbond FW Type. That means: 1.8V. Most programmers (the ch341 for example) are only for 3.2v eeprom types. so you have to use a level converter from 3.2v to 1.8v. If you didn’t do that, you have inserted 3.2v on the motherboard where only 1.8v were expected……

I had to desolder my bios chip and change it to a new one. the old chip was possible to program and verify but it doesn’t work. a new one was able to start my tablet with the same bin file. it seems that my old bios chip has problems at normal working frequencies (20mhz).

After changing the chip and charging the lipo with an external lipo charger my chuwi works well since a couple of weeks.

[Michal]

When I am reading posts about changing bios chip in the motherboard, I am fking scary. Are you everybody working as a repair person in any factory? Or changing the bios chip is very easy and every gsm service is able to change it?

[Bill Christiansen]

OlliFromGermany wrote:

I had the same problem. No sign of life and the battery at 3.1v – fully discharged. (at 3.1v stops the pmic – axp288c) First of all: the BIOS Chip is a Winbond FW Type. That means: 1.8V. Most programmers (the ch341 for example) are only for 3.2v eeprom types. so you have to use a level converter from 3.2v to 1.8v. If you didn’t do that, you have inserted 3.2v on the motherboard where only 1.8v were expected…… I had to desolder my bios chip and change it to a new one. the old chip was possible to program and verify but it doesn’t work. a new one was able to start my tablet with the same bin file. it seems that my old bios chip has problems at normal working frequencies (20mhz). After changing the chip and charging the lipo with an external lipo charger my chuwi works well since a couple of weeks.

Thanks for the additional info, I’ve now ordered a 1.8v adapter. What sort of charger and method did you use to revive the lipo above the 3.1v? I don’t want to buy a special charger but may be able to modify a usb charger to control the current to get it above threshold.

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