8800GT voltage mods

[jason4207]

i had the volt mod done on my 8800gt running at around 1.35 volts under load w/o any problems, i even did some thorough testing but wasn't getting much stable above 780 core and 1950 shader, so i thought the ocp mod might help out, at first it seemed that the ocp mod was helping out w/ stability at higher clocks, but then the temp was rising a little higher than i wanted it to, around 70, started to throw a few errors, and then the comp shut down. The comp would not power back up again, gave a loud whining noise, everything powered on fine w/o the 8800gt power pin in but nothing on the monitor, so i popped in my 6600 and it worked fine, so i had a dead 8800gt after the ocp mod at 1.4 volts load. just thought i would let you guys know. I got the 8800gt replaced, but I doubt i would run over 1.3 volts now and I probably wouldn't do the ocp mod. Maybe I just had some bad luck, who knows, but the soldering was done perfectly. used 1.2k resistors for the ocp mod also.

I killed my 8800GT over the weekend as well. I finally got it back from a month long RMA due to the holidays, and proceeded to bury it after only a few days! I did all the mods w/ excellent soldering work, and used 3.92k resistors for OCP.

I was running it w/ the HR03GT and a nice high CFM Panaflo fan. I put HS's on everything I could. Got it up to 864/2000/1026 at 1.36 idle. Didn't feel comfortable going any higher on the voltage on air. Temps were getting to 52*C w/ ATI Tool. I decided to run the FUR stability test b/c I know it can get the cards hotter than ATI Tool. Walked-away for a second, and when I came back the PC was off, and pressing the power button yielded no result. A flip of the PSU switch allowed the PC to flash on for a 1/2 second , but still no boot. I put my 8800GTS-512 back in and it works fine now.

I disassembled all mods and card still doesn't work. 2 possible culprits.

(1) I see that one of the wires to the vGPU mod had some of it's insulation melted away (didn't see this until I removed the mod). This could be from it laying across a hot chip/component. It may have shorted out, but I don't think this is the culprit.

(2) I cranked down the bolts on the cooler pretty hard. I could see a definite bend in the card PCB. I backed off a turn on each screw, but it was still bent a little bit. I think I may have mounted the cooler unevenly (my 1st mount on an exposed die) and it appears the corner of the die is chipped off a bit. I think the combination of the improper mount and the higher temps proved to be too much for the poor silicon die!

My 1st gfx card volt mod started out great, but ended in an unfortunate disaster!

I might post some pics later...I forgot to bring my camera's flash card to work.

Thinking it was my mount, and not some bad soldering work (it looked darn good if I must say) I proceeded to volt mod my 8800GTS-512. (I know....I'm stubborn, but I have a much better 'feel' for how to mount the cooler now) I've got it all running now w/ the HR03GT on it and the vGPU mod, and vMem buck mod. It was late when I finished all that, though, so no results yet, but the card is idling happily at 39*C w/ my previous OC of 771/1944/1062. For now the VRs are tuned to max resistance. I'll start ramping it up tonight if the wife isn't feeling too needy. I'll post results in the appropriate thread.