Pc, was overheating, now boots, and reboots, then no video or sound.

[Krais]

My pc has been crashing during high graphics usage, on reboot, it mentioned CPU over ttemperature, I took the whole system apart, replaced the thermal paste, used a light amount and spread it thinly, I then replaced all of the components into the case, checked all plugs and connections. But the pc boots and shuts down and reboots, then it stays on but, I have no video at all, through the gpu or the motherboard outputs. Any suggestions on what to check?

 

[OlittoTV]

seems like a motherboard issue. could be capacitors if its an older board which control power delivery and if one or many have leaked this could be your problem. Its most likely the motherboard or PSU