[SOLVED] PC booting issues

[Dark Sorrow]

When I power on my PC it start and suddenly stops even before POST, then PC automatically boot at random after some time.

If PC boots and load windows successfully, the PC abruptly shuts-off at random.

I've a Crosair Power Supply HX850i. This is an replacement that Crosair provided me for a AX860i power supply gone bad.

Processor : AMD FX8350
Motherboard : MSI 990 Gaming
RAM : Crosair Vengeance DDR3 1866MHz 16 G.B.

My build is 5-6 years old.

 

[Shektron]

It is possible that the previous bad PSU has damaged other parts of your system. The best route you have now is to take it to a hardware repair store and let them find out what parts have been damaged. Diagnosing them all yourself would be quite a task.

 

[Dark Sorrow]

Due to current COVID-19 lockdown it's quite difficult to get access to repair shop.
Moreover my PC was working properly for about a year after replacing my Power Supply. If my old power supply had damaged some other components shouldn't the problem have occurred a while back?
What are my other options especially with regards to self diagnosis?

 

[Shektron]

Due to current COVID-19 lockdown it's quite difficult to get access to repair shop.
Moreover my PC was working properly for about a year after replacing my Power Supply. If my old power supply had damaged some other components shouldn't the problem have occurred a while back?
What are my other options especially with regards to self diagnosis?

You can try a few basic diagnostics, like running memtest64, checking for Critical errors in Event Viewer, updating the BIOS and drivers, but other than that your only choice is to start replacing parts, probably best place to start would be motherboard. But I doubt the warranty is still there, and spending money on such an old platform wouldn't be advised.