MSI GTX1070 design fault?

[didi79]

Hi I'm working on a MSI GTX1070 Gaming 8G. Vmem is missing. Strange enough the card otherwise is working: All other voltages are there and the card is even detected. Obviously no image output because of "missing" memory.


This is a picture of the uP1642P. It controls the memory voltage rail. Primary suspect of the fault.

Datasheet uP1642P

Pin 21 PVCC should be 5V. Datasheet says 6.5V max.
But on this card it is actually getting 12V (measured), only a 2 ohm resistor separating it from the 12V rail.
Is that a design fault?

If I replace the IC, should I reroute PVCC to the 5V rail instead?

[piernov]

Re: MSI GTX1070 design fault?

IC is uP1641P not uP1642P. Probably different supply voltage.

[gipsas]

Re: MSI GTX1070 design fault?

Hi,

But card did work before so its some how need to work.

Can you try to look on pcb code of pcb mode. Need to find similar to V347 code.

[ktmmotocross]

Re: MSI GTX1070 design fault?

PVCC should be in range 4.5-26V.

if dont find this how u wanna find fault?

[didi79]

Re: MSI GTX1070 design fault?

IC is uP1641P not uP1642P. Probably different supply voltage.

You're right. How did I miss that?!

edit: Pinout however seems to match typical application circuit of uP1642P. So still useful because I can't find a datasheet for the uP1641P.

[didi79]

Re: MSI GTX1070 design fault?

Can you try to look on pcb code of pcb mode. Need to find similar to V347 code.

I'm not sure what you're asking. Could you rephrase?

[didi79]

Re: MSI GTX1070 design fault?

Ok so there are a few variants for that IC, maybe it is more similar to uP9510 . That one accepts upto 15V on PVCC.

[zapatoo]

Re: MSI GTX1070 design fault?

did you found the solution.......i have the same problem.....thanks in advance.