RTX 3080 Ventus 10GB OC - powers on for 10 secs then off again

[dicky96]

Hey guys has anyone come across this fault?

MSI RTX 3080 Ventus 16GB OC

The GPU powers up, all voltages look OK, Vcore 0.76V, Vmem 1.38V, PEX 0.95V

Then after about 10 secs or so all voltages power back down again apart from 5V and 1.8V.

It does not seem to be temperature related - if I power off and on immediately, it just does the same thing again

I have a power sequence chart that says another voltage powers up after 1.8V and before PEX . It could be MSVDD but I am not totally sure

Does anyone have a schematic or boardview for this one? I could start tracing from 1.8V_PG using datasheets but I thought I may save a bit of time if someone saw this problem before.

[DynaxSC]

Re: RTX 3080 Ventus 10GB OC - powers on for 10 secs then off again

Hi, I would'nt be sure that it's not temperature related.
The silicon in the chips internally can get warm much faster then the case.
I'd give a try with a freezer spray on the vrm chips, just to test if it would prolong the power on time.
The usual powersequence is 5v -> 1,8V, NVVDD (GPU core) -> PEX -> FBVDD (mem).
So something with GPU, PEX and Mem voltage is wrong, probably FBVDD. Possibe could be also a problem with the 1,8V vrm, as it gives the EN signal to NVVDD. Try to look if and which EN signal is missing after the 10 sec's, or better trace it with a scope after powering on. Only way is probably to find the EN signal in VRM datasheet's, would'n expect there is a schematics available for such an new card.

[dicky96]

Re: RTX 3080 Ventus 10GB OC - powers on for 10 secs then off again

Thanks
According to the power sequence chart I have, there is another rail between 1.8V and PEX but I can't quite make out what it is (see attached)

I have the board view for this GPU as well so that will help a lot- someone posted it on my discord. it's here if anyone else wants it

[DynaxSC]

Re: RTX 3080 Ventus 10GB OC - powers on for 10 secs then off again

Impressive this part density on the card, there is a lot what can get broken.

I'd guess the "in between signal" is MSVDD, from the boardview some important power supply to the GPU chip beside NVVDD, 6 phases and quite lot of pads used. Have no idea what it is, didn't had such card/GPU on the bench. But found some track from the driver/mosfets to 5V_PGOOD signal over a resistor, but didn't get into detail. Look for PS_MSVDD_DRVON signal, this probably triggers this supply, maybe somehow "anded" with 1V8.

Good luck in this labirynth