R9 280x - only runs at x8

[Bozog]

Hi, having some problems with an R9 280x, sometimes it will work fine, other times it will crash, but is always only detected at PCIEx8.

Only thing I can fine is one of the PCIE lanes measures 2.2v in diode mode, all the others are 0.6v, all of the 220nf caps are ok and this side measure fine in diode mode too.

Do we think its worth trying to reball/reflow or its more likely a faulty GPU core?

Thanks

[DynaxSC]

Re: R9 280x - only runs at x8

Hi, I doubt that you even use all the bandwith of x8 as this is not a very new card, so I would recommend to do nothing. To go sure make some fps benchmarks and compare to results published in the internet to check if x8 slowens the card. Reballing is always connected with some risk to GPU and board. Card and GPU schould be professionally "baked" 24h before doing this (in order to get rid of the humidity in the board and GPU case, not doing this may result in demage GPU/Board, and I mean not the cooking of the card in an oven, which is the worst what you could do). Also some low quality / older boards can distort themselves during heating and even more contacts can be lost. Doing a reflow with a quite active solder paste would be my first recommendation. However if the card is not stable, reflow/reballing may be the only options, as if the problem is in the GPU not much can be done. Probably you have this correct, but go sure you have the card in the first from CPU x16 slot, usually the second full PCIe slot is x8.

[dragos2009]

Re: R9 280x - only runs at x8

also if the card is idling it would downclock to lower pci ex spec and use lower lanes make sure you stress test it and then check for how many lanes it runs at

[Bozog]

Re: R9 280x - only runs at x8

Thanks for the pointers, I think I will have to try reflow the chip - card doesn't work at all now - no display and error 43

Not bothered about the x8 issue, just thinking it maybe an indication of a solder ball problem.

[DynaxSC]

Re: R9 280x - only runs at x8

Remember to "bake" i.e. preheat the card for some hours (at least 12h) over a preheater at ca 120-140 C, to get rid of the humidity in the board and GPU. Monitor the board temperature during reflow, so that it does not go over 280 C. You can also try to bend the card with caution, and see if the picture comes back, if yes this is an solid indication for a contact issue, if no picture this gives no information.

[Bozog]

Re: R9 280x - only runs at x8

Remember to "bake" i.e. preheat the card for some hours (at least 12h) over a preheater at ca 120-140 C, to get rid of the humidity in the board and GPU. Monitor the board temperature during reflow, so that it does not go over 280 C. You can also try to bend the card with caution, and see if the picture comes back, if yes this is an solid indication for a contact issue, if no picture this gives no information.

In preparation to whip the gpu off, I oven baked the board today @ 100°C interestingly the pcie lane that measured 2.2v (and I checked, it still did this morning) now measures correct at 0.6v