Sapphire HD 7850 2Gb

Seller Notes “Black screen if I installed the driver. If reinstalled window 10 and I am see some part of the screen. That is living room machine and only watch YouTube and Netflix etc.”

  • Resistances & voltages seem normal, vCore a little high at 1.2v, displays until driver load then crashes with heavy artifacts, 2 vertical artifact bars in BIOS screen – likely faulty vram module(s), need some way to test to confirm

Diagnosis

Pretty sure the behaviour exhibited is consistent with 1 to 2 vram chips failing (the two vertical bars). However, being an AMD card, I cannot run Mats to find out which two. There may be a way to work it out electronically (saw somebody short chips in turn and check whether the sepcific chip matches the artefact position). In the meantime, I need to check availability of replacement RAM chips.

H5GQ2H24MFR T2C

These are not expensive and readily available.