Problem rebooting my XP Pro MCE

It just started this morning. I rebooted this morning & the monitor went black & the normally green light was red indicating no signal,I guess. I ended up shutting it down via the power cord. Waited 30 seconds & it booted up fine.
About an hour or so later, I rebooted again. This time the monitor flashed a white screen a couple times,but still had the green light.
I once again used the power cord switch to shut it down. Waited 30 seconds & it booted up fine.
I came in here to get help, hopefully its not dying.

Good news is that I'm able to shut it down completely & start it back up with no problems, so far. I do not have a back up pc to use if this one dies. I'm praying for a miracle & good news from here.
I'd still appreciate some help, thank you.

Sounds like a power supply issue. Only time will tell, if you don't have one to swap out

When I got this tower about 3 years ago, a new power supply unit was put in. I'm not saying it couldn't be it, just letting you know. It works fine when I shut it down & power back on, so I'm not going to reboot it.
Hopefully Santa will bring me a W7 before this goes,hopefully . Thanks for your reply.

Okay, good luck

Thanks,I'll need it.

Well, Santa brought me a 2nd hand W7 on the 23rd so I'm using the XP for a clock since I don't have one.
If it dies,oh well. Its offline.Thanks Tmagic650 for your input.