Dell Desktop will not power up

Dell Dimension 4550

2.2 GHz P4; 2 x 256 MB SDRAM; ...

I replaced the power supply, but still will not
power up. Four lites on the back (A B C D)
flash momentarily, then extinguish.

Unplug, wait one minute, re-power, same.

I have checked and re-seated all the connectors, still same result.

Any ideas? What's the next step?

 

Was you trouble shooting this problem when you changed the power supply? ed

 

Yes, I swapped out the power supply as an attempt to troubleshoot or correct this problem.

 

Try , unplug power supply, pull battery out of mother board, hold down on-off button for a few seconds, let set a few minutes, and try again. Have you tried reseating the memory? [ taking out and putting back in] ?. ed

 

Tunered, thanks, the Dell is back on the air again.

Reseated the SDRAM cards, all internal cables, one more time. Then it came up A-OK.

It's normal for the four rear-panel ABCD trouble lights to flash and extinguish, I've just learned.

Pressing the power button on the front will initiate boot sequence and the lights will change several times before boot starts.

 

Glad you are up and running. ed