Desktop hard to boot after A/C power failure?

[lectrocrew]

ATX full tower, Celeron, Intel D845GVSR, XP professional X86, Intel integrated GPU.
It boots fine as long as I shut it down via 'Start > Shutdown/restart' ect.
But when the A/C power is interupted I have to go through a series of --- 'power supply switch off / front panel power switch cycled on-off / wait several minutes / enable power supply switch / front panel power button on? / and presto! (And sometimes I have to go through this sequence several times before it boots.
Fact: (If I enable the switch on the power supply and hear the cooling fans come on, then it will not boot... But If i enable the power supply but subsequentially have to depress "ON" switch on the front cover before I hear the fans, it boots fine.

I also noticed the monitor gets no input signal while the PC is attempting to boot in this situation.
At the point when I finally get the machine to boot, I noticed that the VGA monitor input indicator light is the first sign of life (green as opposed to yellow).
In other words; After a few attempts with this issue, I now know it's finally going to boot via watching the input LED indicator light on the monitor.
I'm thinking I may have a setting wrong in the BIOS but I don't know. What should I check to resolve this issue?
As always, thanks for any help,
Mike

 

[Transfusion]

From personal experience with a MSI 760G chipset motherboard:
The 350 W power supply was of some random Chinese brand-it did not have a switch on it. I had just finished blowing all the dust bunnies outta the case and plugged the power connector into the PSU. The computer automatically booted up without the use of the front panel power switch. I thought I was hallucinating and pressed the power button once. It shut down without issues. The computer worked throughout the day without issues, too. The next day I pulled the plug and put it back in to ensure that the computer was working as it should, and the computer powered up again by itself. I was just about to walk away when a MASSIVE stream of sparks came from one single voltage regulator near the CPU socket. I noticed that the motherboard was POSTing.   I immediately pulled the plug. *censored* it did not smell good. The motherboard wouldn't power up anymore with a new Hyundai PSU.
For the sake of curiosity, I got the motherboard back out again just now and put another Athlon II X2 240 in it. Its up and running now... but how long will it last?

Does the problem persist if you swap PSUs and reset CMOS?

My monitor's light changes from orange to green before the POST text appears.

[quaxo]

Check the BIOS for an option of what to do in case of a power failure. What is it set to? Should have an option to either remain off or reboot. Toggle it to whatever the other option is from what it is now, and see if that helps any.

I had an Intel D845GB, which I believe has the same BIOS, and it had the option.

[lectrocrew]

I was just about to walk away when a MASSIVE stream of sparks came from one single voltage regulator near the CPU socket. I noticed that the motherboard was POSTing.   I immediately pulled the plug. *censored* it did not smell good.

  I feel confident in saying "that motherboard did indeed have a heart with the will to live"!!! lol.
  Thankfully I haven't witnessed anything like that on my machine... yet...

The motherboard wouldn't power up anymore with a new Hyundai PSU.

Gee, I wonder why? lol 

Does the problem persist if you swap PSUs and reset CMOS?

I don't know yet. I'll swap the PSU and reset the CMOS tonight after my uncle gets through using the machine playing his POGO games (probably ~11pm CST US) I'll post the results then.

My monitor's light changes from orange to green before the POST text appears.

Yes this monitors indicator light does this - normally, but during the situation in question here, the green light never comes on. No text ever appears.
I will have more information on this issue later tonight.

Thanks once again for you help Transfusion! 
_________________________________

Check the BIOS for an option of what to do in case of a power failure. What is it set to? Should have an option to either remain off or reboot. Toggle it to whatever the other option is from what it is now, and see if that helps any

As I posted, I'll do that tonight around 11pm CST US.  I'll need to wait for my uncle to gets through using the machine.
I agree that the Intel D845GB should have the same, or similar BIOS configuration. I'll post the results later.
And to you quaxo, as always, thanks again!!! 

[lectrocrew]

Bingo! 
In the BIOS, under 'power', it list - 'after power failure',  Options are; "stay off/last state/ power on".

This option was set to "last state". I changed that value to 'stay off' and saved changes. 

I've now run 7 sequences of full start-up - then shut off supply power. So far the machine re-starts correctly.
= (especially from my uncle)... Thank you so much for your help quaxo and Transfusion!!!