Solved: Laptop screen stopped working after cleaning its fan.

Status
This thread has been Locked and is not open to further replies. Please start a New Thread if you're having a similar issue. View our Welcome Guide to learn how to use this site.

Qqwy

Thread Starter
Joined
Jan 13, 2013
Messages
5
Hello there, everyone.

I have a HP Compaq 6720s laptop. This is a laptop that is about six years old. The last two years the fan had been extremely loud. Because I guessed that there might be quite a bit of dust inside of the fan, I decided to open the laptop up and clean the fan.

This turned out harder than I'd expected, since the fan is on the bottom of the motherboard.
I used the following video to guide me through the disassembling process: http://www.youtube.com/watch?v=Pxggm5CWnHA

There indeed was a lot(one could say a carpet made out of) dust inside the fan/heatsink. After I cleaned it I assembled the laptop back again as good as I could. I think I did fine, even tough I somehow ended up with a few screws I must have forgotten somewhere.

Then I tried booting the laptop. The power light went on, the fan started to spin but the screen kept completely blank.

As far as I know I've reconnected everything. I rechecked everything and I believe all is fine. The screen seems to be connected to the motherboard through a black and a white cable. (In the video these get disassembled at 6:20). These are connected.

I tried hooking up an external display to the laptop's VGA port. When powering the laptop it keeps blank as well (giving the stand-by flickering of not recieving input). Then again I'm not sure how external monitors normally react to laptops: if they instantly work or if you have to change some settings in your OS before the computer will send the screen through the VGA.


My question:
What might be causing my screen to be black? Is it possible that something on the motherboard is short-circuiting or something because I've opened it? Does it mean something that an external monitor won't work either or is this normal?


Thanks a lot,

Qqwy
 

Qqwy

Thread Starter
Joined
Jan 13, 2013
Messages
5
I have been trying some more things. I've again completely opened the laptop up and looked for things that might have short-circuited the motherboard. I've also tried resetting the BIOS by removing/reinserting the battery from the motherboard.

Still the screen does not get on...

I also read something about static electricity: Is it possible that I broke my motherboard because I touched it?

Thanks,

Qqwy
 

Qqwy

Thread Starter
Joined
Jan 13, 2013
Messages
5
Thank you for your reply, daj. I did not replace the heatsink paste, because I didn't touch or move the heatsink. I cleaned the fan and the space between the fan and the 'exhaust' that the heatsink is connected to (not sure how to call it; the part where the air flows through out of the laptop again). The heatsink including this metal grid structure are attached to the motherboard and I did not attempt to unattach them. Could it still be a problem in this case?

I also tried using the function key with the TV monitor on it by pressing fn + F4 as the function keys on this laptop normally behave. Didn't work. I now also doubt if the computer is actually booting up the operating system, because none of the function keys work, the wireless turn on/off button left of the power switch doesn't react when I press and I do not get any sound(like a startup sound), not even when waiting for ten minutes after turning the computer on.
 

dai

Joined
Mar 6, 2003
Messages
11,198
try a cmos reset


see if it boots into the post screens with both drives removed
 

Qqwy

Thread Starter
Joined
Jan 13, 2013
Messages
5
Removing the hard drive or even both ram slots does not seem to change anything about his behaviour.

I haven't tried re-flashing the bios or whatever it is that the third post is telling me to do because I sadly do not have an USB floppy drive over here. Would the same steps work with a CD-ROM or not?
 

dai

Joined
Mar 6, 2003
Messages
11,198
i don't want you to reflash the bios i meant a cmos reset

it will not start with the ram removed i was referring to the hard drive and the cd /dvd drive
 

Qqwy

Thread Starter
Joined
Jan 13, 2013
Messages
5
Sorry, I need to get my terminology straight. I now know that a cmos reset is the same thing as removing the bios battery. I did this when I had the laptop opened up the second time.

So, and now I tried removing the hard drive and CD/DVD drives...


Wow... when removing the hard drive and the CD/DVD drive the screen will display the boot screen with the HP invent and Intel logos before coming up with an Non-system disk or disk error.

Then I tried re-inserting the hard drive and the CD/DVD drive. Miraculously the computer booted up completely normally.

I don't know how booting up without both drives could've worked, but it somehow fixed it.


Thank you very much for your help!
 

dai

Joined
Mar 6, 2003
Messages
11,198
removing and reinserting the drives would have cleaned the contacts on the drives

a fault with one of the drives could and looks like it was the cause of stopping the boot

glad you have it sorted
 
Status
This thread has been Locked and is not open to further replies. Please start a New Thread if you're having a similar issue. View our Welcome Guide to learn how to use this site.

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

As Seen On
As Seen On...

Welcome to Tech Support Guy!

Are you looking for the solution to your computer problem? Join our site today to ask your question. This site is completely free -- paid for by advertisers and donations.

If you're not already familiar with forums, watch our Welcome Guide to get started.

Join over 807,865 other people just like you!

Latest posts

Staff online

Top