Blank screen on laptop...fans running, hard drive working.

Hello to all once again,
I can't believe I'm going to try to tackle this after the computer problems I've had over the past two weeks, but I have time, so I'm going to!
I have a few Dell Inspiron 1150 laptops laying around the house here that I've acquired from different sources, and I'm trying to fix each of them. I have some that had a bad DC power jack, and I replaced the motherboard in one and it now works perfectly. One that I am currently working on powers up, the fans are running, and the hard drive sounds like it's booting up, but there is nothing on the screen....doesn't even blink! I thought perhaps it was a bad inverter, but like I said, I have a laptop that is in perfect working order, so I used that screen to plug into this laptop, and still nothing! I also tried to use an external monitor....same result. I can't figure it out. Do you think it is a bad motherboard or video chip? It really sounds exactly like the other ones that are booting up, but no picture whatsoever! Any suggestions?

Thanks!

P.S. I already went through the Dell support knowledge base...it's like trying to get somewhere with GPS, and it keeps leading you to closed or dead end streets! No luck there.

 

Replace the memory and see what happens?

 

Sorry, should have told you I tried that! When I ran through the Dell questionare, I did that with removing the drives and all as well.

 

Anybody else? I'd really like to try to figure this out!

 

screen is probably dead ither that or its the mobo

 

Last laptop with no picture I had to service the owner used to run it sitting on the arm of his upholstered sofa.
He fried the graphics subsystem resulting in a new motherboard.
If it is the screen system it is more likely to be the inverter supplying the screen high voltage, than the screen itself. These are small modules behind or below the screen within the lid.

 

I would have to say the motherboard, since as stated in the original post, I switched it with my perfectly working screen my other Dell Inspiron 1150, and still got no picture. Would a bad DC jack cause something like that? That's what the person I got the laptop from said happened...the dc power jack needs replaced.....I just don't want to spend the money on having the jack replaced if it is something else!

 

Without checkeing specs you normally test the graphics on a laptop by seeing if you get video output from the auxiliary VGA socket.

Since you say the fans etc are running I can't see how a power connector could be at fault. Surely if the laptop was short of power the it would just stop?

Of course we haven't yet mentioned the processor. Difficult to diagnose without a laptop version Post card to check for action here.

 

Where could I find a laptop POST card, and about how much are they? I had one for a pc laying around somewhere....never thought of getting one for the laptop! Good suggestion!


P.S. thought I mentioned in the original also that I tried an external monitor....same result!

 

Since I don't know which continent you are on it's difficult to advise, but mine came off Ebay, through a supplier in London. It was not expensive.

http://www.61131568.com

Qui Guan Electronics