GTX 960 power problem

[Carosel43]

For fun i have been buying up faulty graphics cards on ebay and trying to fix them. Its mostly just for the learning experience and a bit of fun playing with hardware. So far a 7850 and 2 gtx 760's have been restored. Mostly just with a clean and new paste. 

 

However, i have a GTX960 2gb that needs more. Someone has mangled it at some point, half the screws are missing and some stickers are shriveled suggesting an attempted reflow? Who knows, but after a clean and repaste it worked with green artifacts and code 43. After a few reboots it repaired itself apparently, drivers install and no green snow. 

 

The issue now is in 3d applications the card screams (so loud it scared me the first time) with coil whine for a short time and then quiets down. Looking at afterburner/gpuz the card hits normal clocks then throttles to about 600-700mhz drawing about 50-53w at 100% load and reporting about 40% TDP. gpuz reports power as the limiting factor. Crank the power limit in afterburner and you get another scream of coil whine, 85w peak at normal 1100mhz clocks for a brief second and then it falls back down to 53w, 600mhz etc. Sometimes it will crash when the load is applied, sometimes it just screams at me a then throttles. 

 

Clearly a power delivery problem, im thinking an inductor has snuffed it? can i test that? could i have a crack at replacing it? 

[Carosel43]

Bit of an update

 

I was poking around trying to find out where there coil whine was coming from. It has quietened down significantly but the card still holds 6-700mhz. 

 

Anyway while poking i noticed that the 3 inductors were different temperatures. The top one was hot, the middle one barely warm and the bottom one roasting hot. I then noticed that poking the bottom one gave me a change in the tone of the coil whine and i can feel very slight movement in the casing. Poking the cold one brought back the shrieking coil whine and gave me a boost in power to 65w and 900mhz. I think its clear where the fault is, i just dont know what parts to get and how to fix it. 

[Carosel43]

Just for info i have been able to fix the card. I decided to whip out my soldering iron and re-flow the solder round the squealing inductors. This fixed the problem for the most part although the card was still unstable and would sometimes crash when a load was applied. 

 

So, i decided to remove the inductors to check the spec and perhaps get more. With no part numbers apparent on the casings i just cleaned the legs and refitted them. The card now seems to run perfectly. 

 

All i need now is to find some screws to hold the whole thing together as its previous owner lost most of them.