I am troubleshooting an R9 290 graphics card with reference PCB
It is not powering up.
I bought a good R9 290 to help me with this. The U300 converter requires 12V input on its upper-left pin and 5V on the red marked pin. As a matter of fact, on my bad card, this 5V does not materialize. It's like 0.25V. We have a short here, because the resistance to ground is only 25 Ohms, and it should be like 50k Ohm.
From here, I have no clue how to further troubleshoot and find the bad component.
I also note some (significant) differences in the resistances of the green marked capacitators, The green side = ground. The 8 ones on the right have 34 ohms on my bad card and 285 on the good one. The C102-C104-C305 have 1.8k ohm on the bad card and 4k on the good card. I have no clue if this is significant and if it is a cause or an effect.
Anyone has access to friends who would know more about this PCB?