I had the same problem with my gaming rig before and it was the PSU that was the culprit as it overheated and burnt out.

Luckily it did not spark and take down the rest of my components especially the video card and the Processor which is the most expensive to replace.

A good motherboard will cost a quarter to less than half of either a graphics card or processor.

Hope you get it checked by a competent technician who can really find the root cause of the issue.