HP 724c PC Power applied, both fans running and green and amber lights on in front but no boot up

[dhbrotor]

I have an HP 724c PC operating on Windows XP. When the Power Supply Unit switch is turned on, both fans run and the green and amber lights on the front of the tower stay lit, but the computer does not boot up nor will the CD or DVD drives open. I already replaced the CMOS battery earlier today. I also tried holding the power button on front down for 15-30 seconds and nothing happened.

[old_geekster]

Dhbrotor, welcome to the forum.

I believe that you have a failed power supply unit (PSU).  Here is a guide to help you troubleshoot the problem.

I suggest checking all of the connections inside and outside of the computer to assure that they are tight.

Please click "Accept as Solution" if your problem is solved.

[wb2001]

After you try the above test, I would reseat the memory modules.

[dhbrotor]

Well, I replaced the PSU with a 430W dual fan new one, reseated the memory modules and checked all connectors but still no luck. Still having same problem, getting power to both fans and have green and amber lights on front, but holding switch down does nothing! Have to turn power on and off from PSU switch.

[wb2001]

OK, now we go to a step by step support Tech page: http://h10025.www1.hp.com/ewfrf/wc/document?docname=bph07173&tmp_task=solveCategory&cc=us&dlc=en&lc=...

Comments:

Step1.1 Bend a paperclip into a L shape. Insert into the Emergency access hole on the CD drive.

Step1.3 Read carefully and remove all items listed.

Step3.1 Can you get into the BIOS is really important. Is the hard drive detected?

While this does not help with the front panel power switch issue, you need to narrow down the Boot problem.

Can you track back the power switch leads, and make sure the plugs are solidly on the pins?