I just had the same trouble that you. I have Pavillion M8240BR, with the same motherboard and now my PC is dead. It's smells like a design trouble, because the "modos operandi" of the error is the same. My computer was working normally, so I turn it off to clean the memory, and when I tried to turn it on, nothing happened.
Note that the first message was posted by Annazandra in July 2008. It' s April 2010. Same problem.
Just to register: I checked my power supply, and it's working normally. I checked the switch power button, the connector button, and it's also working. I tried to turn on the computer makeing a short cut directly on the switch power pins and nothing.
(If you are note sure about the right pin:
check http://h10025.www1.hp.com/ewfrf/wc/documen...3411762&dlc, to get a sketch up of this motherboard, and after that
chek http://www.fixya.com/support/t614458-hp_mc...erboard_diagram to get information about the Pannel 1 connector).
Dear colleague, if you are visiting this page and had the same trouble, leave your post. I will try to get some support from HP about this trouble. It's look like a case for a recall. When we purchase a computer from HP (or Compaq), we are looking for some quality and good and testified hardware. Not for that.
EDIT: Split from older post by someone else, more likely to get assistance with new thread ~ Hamluis
Edited by hamluis, 10 April 2010 - 08:25 AM.