What is the most likely cause for bad motherboards?

[BehindEnemyLines]

Just recently picked up a laptop, and it seems to "work", to some extent. Actually, the only thing that works are the ac plug light (on mobo), power light (on LCD), and battery light (on LCD).

When the power button is pressed, only those lights would turn on (of course, that means the laptop is using the ac plug w/ the battery plugged in ). The hd, fan, and lcd screen don't work. They just sit still and do nothing. What's the most common part(s) in the laptop's or desktop mobo that fail?

I'm not sure, but the laptop has a button (or a pushable pin) near the LCD hinge. When the LCD screen closes, the pin is pressed down. Can a defect in the pin cause such problem since it's either constantly closed or opened?

BTW, the laptop is compaq presario (series 700 and model 715us). I believe every other components work, just not the mobo. Many presarios seem to have this problem, so I'm just wondering if anyone has a "fix" for it.

Moderator note: Please move to the "Highly Technical" forum if this is not on topic.

 

[BehindEnemyLines]

ttt

 

[BehindEnemyLines]

one more try.

 

[Noid]

Did you post this in the "notebooks' forum ...?

 

[dnuggett]

This does not go to the highly techincal forum. The first post that says "do not post your troubleshooting ?'s here" should have stuck out a little.

This may or may not have anything to do with your motherboard. The Compaq Presarios are notorious for having issues with their power supplys and internal switches. How old is your unit?

A defect in the pin will not cause the problem you are stating, it simply turns the monitor off.

 

[kmmatney]

I have the same laptop (in fact I am posting with it). I just pressed the pin and like the last post, it only turns off the monitor. It sounds like something is seriously fried on the MB, probably something to do with the power distribution. I would try starting without the battery, but it probably won't make a difference.