I've tried it with the battery, with pwr sply with battery in and battery out. The fan spins and a few LEDs go on ... so I'm not sure. You know what maybe I will bring it to dealer even if warranty is expired.
Thanks for your time,
Could also be the battery or power supply -- or the power circuity within the laptop.
There's not much the user can fix on a laptop -- I'd take it to a repair shop -- or back to the dealer (even if it's a bit out of warranty).
It could possibly be bad ram. This would be very easy to test. It could also be the BIOS; then you would have to insert a new BIOS chip that matches your exact motherboard (you could probably find one of these online.) Otherwise it could be any number of problems with the motherboard. I know most companies have a repair factory that could replace the whole motherboard at a high cost. If the laptop is somewhat old you would probably be better off buying a new one.
Findings ram is a lot easier than the BIOS. I tried each ram module (DDR2) by itself; I need them both to reap the benefits of the double data rate, do I need two at the same time for it to work at all? What are the odds both ram chips go simultaneously? It was new out of the box, used for (6) months and then done!!
You only need one ram module to run the computer (but yes you would want 2 identical ones to have the dual-channel mode.)
"What are the odds both ram chips go simultaneously?"
With dual-channel mode, a problem with one ram stick might cause a problem in the other one. Make sure that when you are handling ram to be grounded. The best way to do this is to buy a grounding strap, but also I believe you can touch a metal part of the laptop while it is plugged in with the third prong to ground yourself. At least for me touching my laptop will sometimes shock me. I know for certain though that you can touch the inside metal part of a desktop computer while it is plugged in to release your static electricity.
My HP Pavillion dv6700 is doing the exact same thing. Power on and it shuts down in 1 second; no LED codes, no beeps, no POST, no display - nothing. I can actually tear it down completely but have no way of determining whether it's the mobo or CPU. Fan begins to spin for about 1/2 second so I'm assuming power is okay (maybe - I know that doesn't measure voltage, etc.) Also took hard disk out, hooked it up to USB/SATA adapter and can see, read and write to disk. I noticed that the Power & Battery LEDs on front edge will light, but NOT the Drive LED.
Also, repair manual mentions 'Internal Display Switch' in or near the lid hinge. I was wondering if this switch was stuck CLOSED, so I tore down but can't identify it. Repair manual NOT clear on this at all.