Question Having problems with build working then failing to power on again

[Tortoiseshell]

I transferred to Ac power from my rv and my computer wouldn't start. I bought a new motherboard, wouldn't work, despite lights turning on. I thought both were power surge, and it was a capacitor. Tried with multiple power supplies, by the way. So, I bought a third motherboard. No luck. I got another cpu. This time it turned on and worked for thirty hours. Yesterday, it stopped suddenly. Now when I try to start it it won't turn on. AC outlet is getting 115 and motherboard lights are on. I've tried also swapping battery, ram, gpu, power supply.

Any ideas on this puzzle?

 

[CountMike]

I transferred to Ac power from my rv and my computer wouldn't start. I bought a new motherboard, wouldn't work, despite lights turning on. I thought both were power surge, and it was a capacitor. Tried with multiple power supplies, by the way. So, I bought a third motherboard. No luck. I got another cpu. This time it turned on and worked for thirty hours. Yesterday, it stopped suddenly. Now when I try to start it it won't turn on. AC outlet is getting 115 and motherboard lights are on. I've tried also swapping battery, ram, gpu, power supply.

Any ideas on this puzzle?

Is AC power from generator ? it might not be as stable as it should be.

 

[Tortoiseshell]

Nope. AC is from land now.