How to attempt a laptop power control and supply, board level issue?

[mrme01]

Hi folks, soon I hope to attempt a repair on a HP laptop, but I could do with some pointers, I have a soldering station, a pile of dead laptop boards from previous generations and a rather cheap, but working DMM, and the service manual PDF.

Where should I start with where to look?
I retired the machine when it had instant power off issues when tapped between the screen hinge and top of the keyboard, or some places on the palmrest, so a flex issue perhaps?

Machine powers up, but no video, nothing on VGA/HDMI or the internal  interface. Screen assumed known working, as it's an old one.

Service manual can be found if [NB solutions]DAR18D.pdf searched for in your favourite search engine. Would attach, but too large.

[6PTsocket]

The flex cable goes from the motherboard to the screen take it apart and try reseating it. If you can't get video out of the HDMI, the problem could be more serious. When I repaired my HP laptop with similar problems, the video processor had failed and I had to replace the motherboard. I don't know what model you have but there were issues with video failures because they ran too hot. Improvements by HP and after market additional heat sinking seemed to help. Are you a big gamer? That works the video pretty hard. Of course, the best I can do from this end is guess.

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