Random power misfire, it will not turn on sometimes

Hi,

when I turn on, 1 out of 5 times ,the keyboard lights on, but nothing on screen.

If I wait 30 minutes it might work again.

After powering up, does not crash.

It has passed all diagnostics and some stress tests.

Is there a particular part that can cause this? DIY fix?

(More specific that just the “motherboard” please)

Thanks.

Forgot to say - did SMC and NVRAM reset. Deleted OS and reinstalled fresh.