2 motherboards - make one work??

Forgot to say..Motherboards are totaly same  no diferents, just one have two gpu's and second one doesent, but there is spot prepared for another gpu, so i hope reball nvidia gpu from dead motherboard  and maybe works thanks

If you've got the skills and the equipment to replace a BGA GPU, go for it.  Even a basic, hot-air BGA rework station is a few hundred dollars;  the better ones use IR heating and start more in the $5,000 range.

If not, and you have to pay a shop that will even take the job (most won't;  doing this without ruining the GPU, mainboard or both is far from easy), you'll pay more than you would for a replacement board with the GPU already on it.

Remember, you'll be removing a GPU with hundreds of BGA points, replacing the balls and resoldering it -- doing so without ruining the chip or the board is the reason most professionals won't take the job.

And even if you do replace the GPU correctly, you have no way to know whether all the required suppot circuitry is on the board - you literally will need to go chip by chip to verify that everything in the power circuit for the GPU is the same as on the board that originally shipped with the nVidia chip.  Don't discount the fact that manufacturers will omit chips to save just a penny or two per board where they're not needed.

Ok thanks for answer, i got it, to expensive, and maybe motherboard ruin, so better no..Problem is i cant find motherboard with nvidia gpu, so i was thinking about reballing. But after your post, i give up, for sure..Thanks once again.