After pushing the power button it briefly flashes orange and then changes to a steady blue light, the fans are running hard and there is a solid orange light on the motherboard, nothing appears on the video. And it stays that way, the BIOS does not load.  Also, I have the green light on the back of the PC (power supply light) & there are no beeps. I push & hold the power button to exit this state (turn off).


The normal boot is the same except the fans run at high speed for about 1 sec and then drops to normal as the BIOS loads and the Dell logo appears on the screen.
After multiple attempts it did boot normally and gave this message:
"ALERT! PREVIOUS ATTEMPTS AT BOOTING THIS SYSTEM HAVE FAILED AT CHECKPOINT [25]. FOR HELP IN RESOLVING THIS PROBLEM, PLEASE NOTE THIS CHECKPOINT AND CONTACT DELL TECHNICAL SUPPORT"
Can anyone please tell me what the error code means?

Addendum:
When the problem first appeared, I cleared the CMOS, removed the MB battery to no avail. Then I changed the power supply & briefly thought I had solved the problem. The computer did boot normally & went into the BIOS (because I had cleared it). I set the values appropriately & when I exited the machine did not boot up a second time. Fearing I had damaged the 'test' power supply I put it back into its original machine (I have two I530's) & it functioned normally. Putting the original power supply back allowed me to boot on the fourth try, ran the machine for a day & attempted a reboot - no go. Let it cool down & after multiple attempts was able to get a boot again wherein I managed, by using a video camera, to record the above error message.