I have an HP ze4500 laptop which was having intermittent power failures when on battery, so I've been using it plugged in for a while and it worked fine.
While plugged in, it suffered a power failure and I didn't smell any smoke.
Now, when I push the power button, the LED's light up, but it shuts off again after 1 second.... it doesn't even get to POST.
I tried removing the battery, holding the power switch for 1 min. and booting from a/c only, removing the ram and letting it sit for a couple of days... you know, tips you find on google, but nothing works.
What could it possibly be? Motherboard or power supply?
My suggestion would be go to one of the small comp shops where they still fix computers and see if they are willing to look whats up and not charge too much for it. Laptops are really difficult to fix yourself especially with the kind of problem you described and original parts and repairs are extremly expensive.
BTW I was never to fond of HP SoHo line, business line is really a lot less "accident prone" and NC line is the one to go for when buying HP.
Have you tried calling HP? With Laptops and boot issues, the problem is often firmware related. Had some very similar problems with IBM T20s and T21s back in the day. IBM was able to provide a BIOS update that fixed it up.
I basically agree. HP's business line is very solid. Their consumer lines are less so (actually the ones they market under the Compaq name seem better). It's the same thing we saw with desktops a few years ago. Everyone was overjoyed when "Sub $1000" PCs hit the markets. Predictably, quality plummeted with cost.
One example is that in Soho lines from HP, Dell, IBM, and so forth, you DO NOT get to choose who makes you HDD. That typically means Fujitsu, or some other low-cost, low-reliability generic. When I buy 'cheap' laptops for company use I invest in Seagate drives for each, putting the original (always slow, usually unreliable) drive into a USB case for people to use for file transfer. Much bigger than a flash stick and not much more expensive.