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Need to repair my 3970X

VectorX

I have looked everywhere for technical specifications on the 3970X.  Some of the capacitors on the bottom were knocked off and while the traces look okay, understandably the processor no longer works.  I'm hoping it's as easy as replacing said capacitors, but I

1) don't have the originals

2) don't know what their ratings were

Does anyone have any ideas on how to find this information?  A few dollars in capacitors vs a few thousand in a new processor seems like a good trade.

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Can you send a photo of it? You would've had to have gotten incredibly unlucky with which capacitors got knocked off in order for the chip to not function. Usually, the way PC voltages are wired, the caps are done in parallel, so as long as each of the voltage rails have some capacitance, the chip should at least turn on (whether or not it'll be stable is another story). 

 

Anyway, in order to get new caps, you should first try and find the exact package size of the MLCCs on the back. You should be able to get a pair of calipers to measure some of the ones left in order to find the exact package size (I haven't seen the back of a 3970X in person, though in photos it looks like it's the exact same package size on each pad). Then, look for that package size and order the highest capacity capacitors you can. Computers don't really need an exact amount of capacitance on their voltage rails in order to function, and the more capacitance, the better it will be able to clock (usually). As long as you don't go crazy overboard and add so much capacitance that you trip OCP when you turn on the system (with how low capacitance MLCCs are you'd probably have issues getting the CPU to fit in the socket before that happens) there's no harm in adding more capacitance compared to less than stock, so might as well err on the side of caution. Go and solder them all on (MLCCs are nonpolar, so you don't need to verify the direction of them, just fill out all the solder pads on the back of the GPU with these caps) and see if the CPU boots. Again, I would be a bit surprised if didn't have some other damage to it internally. This is still worth doing, worst case scenario is you're out the $10 you'd spend at digikey on a CPU that was already dead, best case scenario you resurrected a ~$2000 CPU, just temper your expectations for if this will work. 

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image.thumb.jpeg.ab0c7de91563e6d9d0d058bf8133250b.jpeg

 

So far I've identified (I think) the MLCC as a 4 part 0306 capacitor, I'm just not sure which type to get or if that's even the correct size.  I measured with my calipers but even accounting for tolerances, it seems like the dimensions don't quite match up.  The rest of the CPU is not damaged, so I'm hopeful that it's a filtering issue caused by the missing capacitors.  It doesn't look like it got the Linus treatment at least...

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