[laptopuser]

My Dell Inspiron 2650 15" LCD won't work, when I boot up, it just displays a blank screen, but when I connect an external monitor and can see windows and do what I need to do. Does anyone know how to troubleshoot the LCD. I've taken apart my Dell, but I'm not sure on how to troubleshoot the connector to the motherboard.

Thanks

[kiwiguy]

Is the "blank screen" a totally dark screen?
If so, try shining a torch real close, if the backlight has failed then you *might" just see something on the screen

Or is the screen backlit, but no info being displayed?

The above should narrow it down a bit.

[laptopuser]

I forgot to mention what I have tried to solve this problem. I've tried adjusting the brightness and I usually get a bright white screen or a dark screen, but you can tell it is still on. I've also tried removing the battery and unplugging the power source, then holding down the power button for 10 seconds and plugging the power back in and turning it on. The last thing I tried was upgrading the Bios. None of this worked. Is there a way to volt meter the connector or something?

[kiwiguy]

Sounds like the backlight is on OK.

So the video data is not getting to the screen.

That could be a cable problem (its a tricky bit of cabling through the hinge) or it could be an electronics failure in the screen driver.

"voltmetering the connector" is a bit simplistic, a voltmeter will not tell if there is data or not.

The problem is, the fault could be as simple as a failed cable, a poor connection or as complex as a failed screen driver chip. Without a raft of sophisticated test equipment (or better still a full set of replacement parts to substitute) there is no easy answer.

Upgrading the BIOS? About the most unhelpful thing, given that the external screen works there is no way the BIOS is involved. A failed BIOS upgrade (and unfortunately that does happen quite often) destroys the laptop usually. But you have not suffered that fate, whew!

Apart from checking the cable, (but unless you have a spare to try, its not always going to be possible) then I recommend a visit to the laptop doctor....