T40 no post issue

[pcgolfer85]

I am currently working on a customer's T40 and I have run into a very frustrating problem.

I am almost positive that I have a bad system standby switch. The switch is located on the end of the LCD cable. I am trying to find the appropriate part to replace the one I have.

Also, has anyone ever had this same issue?

The symptoms that the T40 is experiencing is when the power button is pushed, I get light response but no video. At first, I thought it was the motherboard so I replaced it, but I am still experiencing the same issues.

[aaa]

Don't forget that there's the vga port (plug in a monitor) to help narrow down things.

[richk]

Often light with no video (backlight on, no data) is a bad cable, or cable unplugged from back of panel.

[pcgolfer85]

The reason I think the laptop is not getting past post is that I get no operating system sounds and there is no hard drive activity. This is what led me to the conclusion that it was the system standy switch on the end of the cable. The system can't boot if it thinks the lid is closed.

[richk]

It will go to the bios if the lid is closed. In fact, with ext VGA and dock, you can start and use the machine with the lid closed with ext keyboard