How to fix my PowerBook g4 that takes 3 times to power up right

I was wondering how to fix my PowerBook that takes three times to get it started but once it’s get to the loading bar the screen goes black but power is still on

I think it could be the heatsink it self because at first it was the RAM I cleaned it with Isopropyl alcohol to get any dirt and dust of the RAM port but that didn’t do anything. Or it could be the hard drive deading but I don’t think it would cause that issue.

I feel like the computer wants to work but just trying to figure out what is causing the issues to take 3 times to push the power button to get it to work properly.

When I push the power button for the 1st time the light comes but the sound doesn’t and screen stays black. But when pushing it the 2nd time it the light comes on but the fans will sometimes start to rev up or the sound will play but the screen doesn’t show anything.

On the 3rd time it will power on light and sound will work and screen will turn on but once it get to the loading bar it will go black again but the computer will still run

Also when it does go past the loading bar the screen stays on but then goes black without having the fans ramping up.

I redid the thermal paste but still nothing, the only thing I haven’t done was switch out the hard drive.