ATX cycling fault?

[Jon S]

about 3 seconds after applying mains power it stops and restarts.

YES ATX has control of the power supply, so it really does not sound like there is an issue with the PSU.

There should be an option to display Power On Self Test results to the screen, and to perform all the BIOS POSTs. It does want to and is trying to tell you what is wrong with it.

"Some older Dell computers use an alternate key sequence instead of <F2> to enter System Setup. These key sequences include:

<Ctrl>+<Alt>+<Enter>
<Delete>
<Fn>+<F1> (laptop computers only)
<Fn>+<Esc> (laptop computers only)"

http://www.techrepublic.com/i/tr/dow...rror_codes.pdf

First you need to know that the CMOS memory (that stores all the BIOS settings) has not been corrupted or blanked due to the battery cell on the MB not being charged in use or just demise from natural causes.

Get into the BIOS and be sure that the HDD(s) are configured.

Clearly an awesome opportunity to get an Apple :-)

Jon