It's my first time to repair video card (MSI RX 580 8gb)and before starting disassembling, the video card is detected by OS but no hdmi signal. I have video signal on my onboard hdmi but not from video card. Of course the signal is from Haswell CPU. On GPU-Z gpu is detected but not memory and no sensor like speed and temp. I uploaded dif vbios and with one of this GPU-Z see 8gb video but samsung not hynix as it is on the board and of course zero speed and temp. I disassembly the board and no shorts on vmem, vcore and other. Next I'm trying to measure the voltage under the supply but my question up to this point, is what should I expect. Thanks.
You need to know where to measure for 12v, 5V, 3.3v, 1.8v, and Vmem. Once you have this info, you can start narrowing things down. If 5v is not reading 5V, you'll need to fix that first before measuring anything else.