#1 [Problem] Experimental Dell Wyse 5070 BIOS doesnt Boot by CopyAndPaste 27.09.2021 19:35

Hi,

I've been experimenting with a couple of Dell Wyse 5070 computers I have spare (part payment for an old job I did some time back).

Having bought a EPZ2019 USB programmer over lockdown, I decided to try some of the basics out with the device - I'm a computer tech by trade but don't have much experience with the IC side of things.

I stripped down one of the 5070's and found that the BIOS chip to be a Winbond 25Q128FWSQ-1831. After searching google I found this chip to be of 1.8V, so I've used the supplied 1.8 adapter found in my EPZ2019 kit. I've also used the cable clip as well, to avoid de-soldering the chip.

The mains power adapter had been removed from the computer, as well as the CMOS battery - the device was fully discharged of power before work commenced.

After starting up the EPZ2019+ Programmer App, I selected the Winbond 'W25Q128FW(1.8V)' from the list of available chips, selected size 16MB, Pagesize 256 and speed 12MHz (I've tried this whole process at 6MHz and made no difference, 3MHz doesn't work at all).

I successfully read the contents of my chip and saved it to a .bin file. After checking the file in HxD, I found information related to the computer (Dell SN etc).
I followed this with erasing the chip of its data - this was successful, after which I re-read the chips data showing blank information.

At this point, I opened the previously saved .bin file and wrote the file back to the BIOS chip - this completed successfully. I then verified the contents, which also completed successfully.

I then rebuilt the machine and powered it back on. Surprisingly the computer did not boot. A meaningless series of lights flashed on the front of the computer but nothing else.
After wondering what had gone wrong, I re-stripped the machine down, removing all power sources and BIOS batteries as well as draining any static.

Once more, I read the contents of the BIOS chip and ran a comparison of the result with the original .bin file - both are identical.

I can't quite figure why this would happen? Is there some kind of preamble within the extracted .bin file that needs to be removed before writing back to the chip? Is the chip actually larger than the stated 16MB of space available?

If anyone has any advice I'm be very grateful of your input.

Thanks

Edit by Fernando: Thread title customized and shortened

#2 RE: Writing Dell Wyse 5070 BIOS - No Longer Boots - Experimental Machines by MeatWar 27.09.2021 23:14

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Why flash the same dump in first place... or did u mod the original dump and the flashed.
Doesnt the board has a service jumper?
User manual has several descriptions on Error code LED.
This motherboard has several security features... this is bad for a random/blind flash operation.
Dont know if has EC FW that needs flash also.
Sure only 1 SPI chip?

#3 RE: Writing Dell Wyse 5070 BIOS - No Longer Boots - Experimental Machines by CopyAndPaste 29.09.2021 00:41

I altered the service tag in the bios to see if the bios file would write correctly once changed - this hasn't been the case though unfortunately.

The motherboard does have a service jumper - when changed to service mode there's no difference in functionality, simply 2 flashes of amber and then 1 longer flash.
Apparently this indicated an issue with the CPU. I've since reflashed the BIOS with the originally read unmodified .bin file, but still no activity when power is plugged in.

The strange thing is that now technically the BIOS chip should have the same data that I originally read, so it should be back to square-one again.

There seems to be only one BIOS SPI chip, this being the Winbond chip. There's also a MXIC 25L1006E (3V 1Mb Serial BIOS chip) and MX 25L4006E (3V 4Mb Serial BIOS chip) which after some Googling don't seem to fit the specs for the computers BIOS data (they're physically quite a bit smaller too).

It's almost like there's something that the USB programmer isn't able to read within the chip, but you would think that using a programmer clipped to the board would provide 'true' data on the chip.

#4 RE: Writing Dell Wyse 5070 BIOS - No Longer Boots - Experimental Machines by MeatWar 29.09.2021 00:47

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https://vinafix.com/threads/dell-wyse-50...dp-d90d7.26280/

#5 RE: Writing Dell Wyse 5070 BIOS - No Longer Boots - Experimental Machines by CopyAndPaste 29.09.2021 19:27

Thanks for the link MearWar.

Is VinaFix a legitimate website then? Its just that I'm reluctant to part with cash if its a scam thats all. Thanks

#6 RE: Writing Dell Wyse 5070 BIOS - No Longer Boots - Experimental Machines by lfb6 29.09.2021 22:00

Why so complicated? If there's a couple of these machines dump the next bios- a valid dump this time, meaning 2 or 3 dumps which have to be be a 100 % identical, structure (UEFIToolNe) should be comparable to stock bios, no additional comments or markings in log, and a comparison of stock bios region to dump should give no differences for the static parts (but unfortunately it's TXE).
Either your dump has errors or your reflash wasn't valid or it's a problem not related to the bios/ this firmware.

#7 RE: Writing Dell Wyse 5070 BIOS - No Longer Boots - Experimental Machines by CopyAndPaste 29.09.2021 22:32

Funny you should say that, as that is exactly what I've done this evening - I took a dump of the BIOS of the working computer and compared it to the BIOS of the faulty computer - after running multiple attempts I compared them all systematically to find that they were all identical.

I'm wondering whether Dell put some form of protection on to their boards to prevent any changes to the BIOS chip being made - on possibly as I flash it on-board via the clip, whether this has made some of the circuitry faulty in some form?

#8 RE: Writing Dell Wyse 5070 BIOS - No Longer Boots - Experimental Machines by Thanatos_VecP 14.10.2021 17:34

Zitat von CopyAndPaste im Beitrag #7
Funny you should say that, as that is exactly what I've done this evening - I took a dump of the BIOS of the working computer and compared it to the BIOS of the faulty computer - after running multiple attempts I compared them all systematically to find that they were all identical.

I'm wondering whether Dell put some form of protection on to their boards to prevent any changes to the BIOS chip being made - on possibly as I flash it on-board via the clip, whether this has made some of the circuitry faulty in some form?


You should be able to change Service tag using Hardware Programmer by simply changing the Binaries and flashing it directly back on. I have done it maybe 500+ times on 5070.

The BIOS off 2 different device will almost never be identical, with that said, you cannot flash a working BIOS from one to another, no matter if they are exact model.

Did you remove the BIOS chip from the board to re flash? or use test clip? If you removed from board and re-flash does not work, it is likely a programming error, improper re-solder or damaged chip etc. If using test clip, you need to have power on the board to successfully program. You can put the jumper on CMOS CLEAR while reprogramming to prevent any attempted booting or reading of BIOS chip during flash.

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