Rear camera failed shortly after replacing logic board

Shortly after replacing the main logic board on my s5, the rear camera came up with this error. It did work for a few days, so I can only assume it is either conincidence, or I lost one of the heatsink pads used for the main camera controller, and it over heated.

I tried a replacement rear camera module from ebay - that I stupidly thought was genuine - but the phone wouldn’t get past the splash screen with this in.

Does anyone know what the likely fault is? IC on logic board, or camera module itself? I would like to know peoples experiences before wasting more money on another camera module.