01-09-2012 05:26 PM
After a general power failure last night, my HP Pavilion Ultimate d4999t CTO will not power on. The LED on the power supply is green, but pressing the power button on the front of the chassis does not start the computer. I have unplugged the computer and let it sit for 10 minutes, then tried again.
How do I determine whether I need a new power supply or the motherboard has been damaged? Is this something only a technician can find?
01-09-2012 07:08 PM - last edited on 02-21-2017 04:27 PM by OscarFuentes
Try the following procedure and see if you can isolate the issue. Don't skip any steps.
01-11-2012 09:18 PM
I followed all of the steps and still no joy. I discovered that even with the green LED, the fan in the power supply is not turning. I have ordered a replacement power supply by part number 5188-2859 or DLT350AB-8 A (seems to be a standard) from http://www.itwinkle.com/hp35posu51.html for $36 plus $11 shipping.
The power outage zapped one of my HP Media Vaults, too, and several nieghbors lost gear.
I'll reply when I have the new power supply installed.
01-12-2012 08:30 PM - edited 01-12-2012 08:31 PM
The fan in some of the new power supplies is thermally controlled. I doubt that the HP PSUs are that sophisticated. I hope tthe replacement PSU solves your issue.
05-31-2012 12:03 AM - edited 05-31-2012 12:53 AM
Here's what worked for me to get the system to boot.
- Unplug power cord from the wall
- Then unplug the motherboard p1 connector (that is the big connector from the power supply)
- Wait 5 minutes until green light stops flashing, allows capacitors to discharge, and magic happens
- Plug the power cord back into the wall and it should now have a solid green light on the back.
- Now plug in the motherboard connector. Yes , apply power first, then connect the motherboard
- Power on the system!
I forgot to mention, this all started after an unplanned power outage.
The only problem, every time I unplug the computer, I have to do this procedure to make it boot again. Shutting down the computer normally, and leaving it plugged into the wall, I have no issue. Any thoughts on whether this is a motherboard issue, a power supply issue or something else?