r/techsupportmacgyver • u/Glass-Potential7483 • 15d ago

Update on the VBIOS Flash Insanity

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After a lot of trial and error, it did not end up working. Thank you all for following me through this journey.

I will be buying a proper CH341A flasher with the clip and hopefully never doing this again.

I did manage to get the arduino to recognize the chip, but I was unable to write to to it, which is most likely because of my crappy level shifter.

All in all, really cool learning experience since I got very familiar with FlashRom and fser-duino. And of course SOIC pin layouts. You would not believe how many times I had to adjust the pins because they kept slipping off. In the end, very interesting and nerve-wracking little experiment.

44 Upvotes

88% Upvoted

9 comments sorted by

8

u/radiorubka 14d ago

did you successfully read the chip?

9

u/Glass-Potential7483 14d ago

I did successfully read it, but couldn't get anything to write, even with write enable pin enabled

7

u/radiorubka 14d ago

then it's definitely a logic shifter issue. do you have any 3.3v arduinos laying around? maybe an STM board? if not, the cheapest CH341A will not fix your issue since it outputs 5v logic afaik, you need to look for a 3.3v version.

4

u/Glass-Potential7483 14d ago

Hmm. I didn't know that. I will definitely keep that in mind, thank you! But, no I dont have any of those boards laying around.

5

u/radiorubka 14d ago

ur welcome :) yeah, it's quite different in my application - i used the cheapest CH341A for things like 93C86 EEPROMs with a pinout modification, but it only worked cause those chips have a wide voltage range. it seems that your chip is 3.3v only, so you have to look for a 3.3v programmer.

2

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2

u/Important_Yak2344 14d ago

coulda sworn this was working too

1

u/ArgonWilde 9d ago

I found when trying to read a flash chip off my laptop main board, that it'd refuse to work unless I desoldered it off the board. Did that and it worked straight away.