Looking for Gigabyte GTX 760 Voltage Points or Schematic or Genral Repair Help

[Webserfer]

Got myself a box of faulty video cards and 2 of them were 760 windforce editions. One has a faulty video chip but the other one kicks the fans onto full with no image meaning that voltage isn't getting somewhere.

I tinkered with it for a few hours and managed to clear a shorted surface cap but still same issue.

 

Wondering if anyone here has or can point me in the direction of a diagram or something that can tell me where to test for voltages so I can figure out which circuit is dead?

I'm OK with a soldering iron and the cards dead already so not afraid to get right into it.

 

The cards number is GV-N760OC-2GB REV 2.0

 

Also, looks like this

[paprikman]

7 minutes ago, Webserfer said:

other one kicks the fans onto full with no image meaning that voltage isn't getting somewhere

Can be a dead bios or vram chip. Did you check all of these? They're marked and, actually, quite easy to stop without a full board map.

[Webserfer]

16 hours ago, paprikman said:

Can be a dead bios or vram chip. Did you check all of these? They're marked and, actually, quite easy to stop without a full board map.

How would I go about checking those?

[paprikman]

2 hours ago, Webserfer said:

How would I go about checking those?

Just like any other chip. Check resistance between its in and out points. If it's infinite, then no current is passing through. You can do this with a simple multimeter. But yeah, you have to find info about that particular chip first

[Webserfer]

Did some further testing today and it's looking like its not a ram or the bios maybe.

 

I'm lucky enough to have an almost identical windforce 760 to compare too. Got some voltage readings off it after working out what does what and where the input to the chip is. The working 760 gets 0.8v on the input, the dead one gets just over 0.1v.

 

I did a real bodge test, by putting a nearly dead AA which would have similar voltage onto that rail and the card doesn't do the instant fan spin up.

It starts normal but as the fans ramp a bit as it starts pulling current which the dead AA cant handle and it goes back to fast fan mode.

 

This means the problem is almost definitely on the voltage supply side. Either something else is shorted or the original short took something else with it.

The fact theirs a voltage at all maybe (im learning as I go) might mean some of the phases are working and some aren't (wild guess).

 

Anyone got any pointers where I should look next or what I've found so far could mean?

I tried to look up info on the mosfets but google said no.

[TheAUSDude]

I have an issue Kinda slimmer but I found that my MOSFET got fried and I'm wondering on how much damage it would have caused like I know the core still works but power delivery Is not stable Is was the 2nd from the bottom and furthest from the chokes