Compaq R4000 keyboard problem

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I use the laptop everything was ok before then suddenly it start beeping and all kind off window opens up by it self and I could not do anything just hard boot to stop the noise. Sometimes comes back normal for a while after restart, but after a while it goes back to same beeping and opening windows again. At that time nothing works, no mouse or keyboard. I have to shot it off with the main power button. I have seen this on the keyboard with a spills off a liquid, but in my case there was no spillage done. I even tried another keyboard which I know is good with the same result. I think it must be a short somewhere on the motherboard or a chip is giving up.
 

kimsland

Posts: 13,806   +3
Remove the keyboard

http://www.bixnet.com/meinguforcor.html
Scroll down the page a bit

Or just download the service manual
http://h10032.www1.hp.com/ctg/Manual/c00364919.pdf
Section 5.8

Reconnect the connections to the keyboard (By the way do you mean that you already replaced this keyboard?)
Also turn the removed keyboard over and tap the bottom to allow any debri to fall out. You can use a vacuum cleaner, but you need to be careful not to suck up the keys!
 
Yes I did try another keyboard from another working laptop with the same result. Now when I boot the keyboard does not work at all. Even in dos prompt before Window starts the keyboard do nothing I can not access the bios pressing anything. I have never seen something like this. I will try to reset the keyboard plug. One more think I noticed is the switch to disable the mouse stays on all the time. I will press the switch for the mouse and the light stays on. Maybe this has some kind of connection between the keyboard problem.
 

kimsland

Posts: 13,806   +3
Directly under the keyboard (power out, and adhereing to anti-static precautions)
Push down on the daughter board, that is plugged into the motherboard

Yes it can be a mousepad problem (or circuitry) you might want to reseat that connection too.
 
The first thing you want me to try I am lost. "Directly under the keyboard (power out, and adhereing to anti-static precautions)" Can you be little bid more specific please. What I should do there? I did do the pushing all over, reset the keyboard with no change. I will have to take this apart and report back. To get to the mouse I do have to take it apart anyway. When it will be apart I will look for a bad connection on the daughter board right? Could it be a faulty mouse too? Well I think I will have to do elimination process. I still think it has to do something with that switch to disable the mouse.
 

kimsland

Posts: 13,806   +3
Taking it apart and reseating everything is good (except CPU heatsink - otherwise you'll need to re-thermal paste it)
 
I did took it apart today and reseat all the plugs then put it together, but I have not seen anything out off alignment. I did little bit of cleaning and blow out some dust. Which I think it was not as bad as I have seen before on some other laptops.The beeping is gone for now. I hope it will last. R4000 does not have any daughter board. Laptop has been running now about 3 hours. I will post if the beep come back. I would still like to know what it cause that problem. Even the switch for the mouse works on and off. Could it been an over charged capacitor well everything was apart for awhile? Just a speculation and I am worry it will come back. Thanks Kimsland for your help
 

kimsland

Posts: 13,806   +3
Could it been an over charged capacitor
Possibly, in this case you would remove all power and hold down the ON switch (for 30secs) to disperse all internal voltage.
But it's better now that it has been cleaned, a bit.

The fault could have also been due to heat, or even bad connections or impedance (resistance due to debri) or arcing (conductance) across tracks from dust.

Too much speculation though, It's fixed :)
 
We learn every day. The small things I would never think off " (resistance due to debris)". Like It still works so cross my fingers and hope that was it. It actually make sense, because like I mention before I did not seen anything out of ordinary. Thanks again kimsland.
 
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