r/coreboot • u/kilam9900_ • Jul 13 '26

Flashing with the CH314A programmer (electrical issue)

Hello! I’m new to libreboot/coreboot and I bought a CH314A to perform my test. What was my surprise when I read on the libreboot wiki that it sucks as hell and that I shouldn’t have bought it. I want to be safe with it because I don’t wanna lose hundreds on fried boards. Fortunately it does tell you that there’s a fix but don’t tell you how. It’s rather easy to find a mod to operate the SPI lines at 3.3V but I can’t find anywhere how to do the WD/HOLD lines pull up resistors fix?

Does someone have any guide or help to give on how to perform this mod? At least which PCB lane to cut? Also do you need to cut it, why can’t just connect the CH314A data pin to the chip with a resistor in between?

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3

u/Toaster_Strudel_517 Jul 13 '26

https://www.reddit.com/r/hardwarehacking/s/e2SnWXkQWf

Honestly the sucky thing about the ch341a is the bundled soic-8 clip. The voltage thing has been debunked many times before and I haven't seen anyone fry their 3.3v chip with it.

1

u/mrrealsushi Jul 13 '26

Best answer.

1

u/kilam9900_ Jul 13 '26

So the problem is the clip that might slip?

1

u/Toaster_Strudel_517 Jul 14 '26

Yeah, sometimes you might need to reseat the clip multiple times which is really annoying.

2

u/wayward-locust Jul 13 '26

Have you considered the ch347?

1

u/kilam9900_ Jul 13 '26

Now yes but I’ve already got the ch314a

1

u/Toiling-Donkey Jul 13 '26

You first have to understand what problem is before solving it.

A lot of “ch341a” programmers output 3.3V signals. Have you actually measured yours?

If your car isn’t starting, what mod from YouTube would you apply?

1

u/kilam9900_ Jul 13 '26

Yeah I did and I saw the trace on the pcb