Computer will not boot, cycling

[KKid]

 I am writing  on my on my Dell Laptop.  A few days ago  when starting up my HP Desktop, I saw what looked like a repair

screen and whle I was a bit groggy I saw "Press Enter"  and did it.  I don't know what line I was on, and believe the

computer was damaged by that.  Since then, when I press the power button, there is the usual "whoosh-whoosh"

sound and the white hard drive LED on the front lights up.  This LED may remain on for a few swconds before shutdown,

or it may stay on for sometime.  If left alone the computer shuts down and then restarts.  The Monitor is black (in standby mode) all the time, power light is on.

  I have tried all of the repair items in the Forum with no luck.  Please reply to wrapa3@gmail.com (laptop)

 Thanks for any help.     KKid

[Grzwacz]

Hi KKid

I will try to assist you with this.

I had this model. What is happening to you happened to my system about six months ago.

Thoroughly cleaned all fans and heatsinks.

Replaced (really only connected the second power supply to the 4 pin and 24 pin MB connections) the power supply with a known good one. Changed the MB CR2032 battery. Used a spare front panel reset switch from a old disassembled tower to short the power switch pins on the MB header.

Pulled the RAM. Then tested each memory slot. Tried known good replacement RAM.

Removed the discrete graphics card. Tried using onboard graphics. Tried a known good replacement graphics card.

Disconnected power to all SATA devices. Disconnected front card reader from the front panel MB USB 2.0 header.

Tried booting the system with only a monitor connected.

Examined the MB for thermal damage or bulging/leaky capacitors.

Nothing worked. 

I concluded the MB or a critical component in the motherboard had failed.

Grzy

[KKid · Accepted solution]

Thanks for the help.  I have suspected the boot battery all along, and am now trying to replace it if I can find

an identical one, and see if this is the problem.

      K

[KKid]

   Since my wife uses this desktop in her small business she insisted on replacing the tower while I troubleshoot

this wreck-- a new HP is on the way