Getting 0.0VDC on the bottom of these mosfets (other side reports 23.03 +- 0.05 VDC) -> Assuming corrupted VBIOS Pin 8 on vBIOS has 3.36V on power up plugged in PCIe and to PSU 12V2A rail -> vBIOS has power and the main rail is working.Ĭhecking pin 8 on the VBIOS while the GPU is in PCIe + PSU on a system that boots gets me 3.36 VDC -> VBIOS is getting power. Probing from 12V in to VDDCI inductor gets me 0.22 ohms vBIOS Temporarely this has been solved through jumper wires on traces. When testing the pin 8 (vDD) doesn't have the expected 3.3v which would point to board design having two vBIOS locations where only one is used, pressumably to make the second location work the board needs reverse-engineering to know where to add the components to establish the connection.

Which is same place as the Gigabyte AMD Vega 56 that is not populated. This damage goes 2 layers deep and exposes one of the board traces, for permanent fix this has to be covered with insulation and create new traces with pads for the pins.Īlternatively, the reference AMD RX Vega 56 SEEMS TO have vBIOS on the back side: My hot air was set on 260C, but it seems that something broke inside it and set it to 400+ that damaged the PCB. Requires more diagnostics for other components, but i don't know what are the expected voltages and the boot sequence (help-wanted)ĭiscovered manufacturing defect on the highlighted area I checked all the 'bigger components' for conductivity and i couldn't find anything faulty. The cooler is fine i connected it to 9V battery and the fans happily spin.Ĭonnecting the GPU without a cooler to a system doesn't give me a display.Ĭonclusion: The cooler is not causing the short PCB Short to ground preventing the VBIOS boot. GPU connected to a healthy system results in no fan spin nor display on startup. I have AMD Vega 56 (GV-RXVEGA56GAMING OC-8GD rev 1.0) that doesn't have signal nor fan spin on system startup.

Rx vega 64 fans not spinning