I'm currently working on a Dell Latitude D820 running Windows XP SP2.
The system is refusing to power up. When you press the power button you get the click of the disk drive and a slight buzz from the hard-drive and the Scroll-Lock, Caps Lock, and Num Lock, Power and Hard Drive Activity lights all light up then Scroll-Lock, Caps Lock, and Num Lock go off as well as Hard Drive Activity.
The fans don't power on and there is no response on the screen. I've tried connecting an external screen incase it was a fault there but there is still no response.
I've also tried taking the RAM out to see if I could produce the standard Error Code on this machine for faulty RAM (Scroll-Lock and Caps-Lock flashing on boot-up) and the test was positive. They did flash with the RAM out, and stopped flashing on power-up when I refitted the RAM.
That leads me to believe it's at the very least running the basic startup checks but then for some reason isn't getting any further.
On a wild-card try I tried using a boot disk in case the hard-drive was causing some sort of fault but there was no difference.
* System turns on but no obvious turn on signs other than power light
* Neither on-board or external screen shows any input
* Start-up checks for faulty RAM etc seem to be running OK
* CPU fan is NOT running.
I was thinking along the lines of the system might have a sensor that detects a fault in the CPU fan and won't power-up is fault is present to prevent overheat as I have found this on a old Acer machine, but I don't' have a spare fan to test and would like to confirm before spending money.
No, nothing is blinking. When power button is pressed the HDD status light flickers a few times, and the power-light comes on but that is it. The only response from any key press is when power-button is pressed again and the system turns off.
As mentioned before the status lights error do appear to work though, as if you take out the RAM you get the correct error light repines code with num lock, caps lock and scroll lock for missing RAM.
Thought I had replied to this with final solution but it appears not. Ooops.
It turns out my original suspicions were correct and it was a fried motherboard. Laptop was a write-off as the cost of replacing motherboard, and any other potentially damaged components, would have been more expensive than replacing the laptop.