Any laptop or LCD screen gurus out there

[Legacy777]

The screen on my laptop went blank about two weeks ago, and I'm trying to determine whether it's the screen, the cable, or the inverter, but haven't been too sucessful in determining which. I have gotten the screen to come back up for a few seconds during testing, but it just randomly does that.

Here's a thread on Dell's forum with more info.

http://en.community.dell.com/support-fo ... 91814.aspx

Thanks

[Someperson]

possibly a broken wire in the harness, or a solder point let go.

[Alphius]

Shine a very bright light at the screen. If you see an image faintly then it is likely the inverter or backlight went out.
If the screen is completely dead, it is most likely a failure of the motherboard or video harness to the screen.

With as cheap as laptops are nowadays, have you thought about just buying a new one? If yours is no longer under warranty it very well may be cheaper to replace than to repair.

[912126]

Mine did same thing. It had a video out /monitor port so I was able to connect it to an old monitor and determine it was just the display. Later found it was the inverter.
Inverter was cheaper than the backlight.

[Legacy777]

I have not beem able to see any faint image in the screen. I've shined a light, but will try and find a really bright one.

I know the video card is good because I have it hooked up to an external monitor and I have my mom's laptop (same model) which has a different screen, but it worked when I hooked it up to my laptop. So it's either the wiring, the screen, or the inverter. I just haven't been able to diagnose which. An inverter is about 25 bucks, but I don't know if that is the issue...it might be. The somewhat intermittant nature kind of leads me to wiring, but I really don't have any concrete evidance.

[Legacy777]

Just thinking out loud here....my screen has two CFFL's in it. I'm assuming the chances of both going out at the same time is probably pretty slim. Unless if one goes out, the other is designed/programmed to shut off as well.

If we assume that isn't the case, then that puts the problem back on the inverter or the cable. I've verified that the video card outputs signal to my Mom's laptop screen, which also rules out any lid closing switch.

Does that sound logical? I'll try and measure the input voltage to the inverter to see if it's receiving anything. If it is, then I'm leaning towards the inverter. If the inverter is not receiving a good input voltage, then I'm leaning towards the cable.

[Alphius]

Given what you have said, I would bet my money on it being the inverter. For $25 it's worth a shot.

[fireman2101]

From what you said I would lean towards the inverter also. That is (in my experience) what normally goes first. I would look on ebay if you can find a deal on the inverter and bulbs together. With already having it all apart it would be easiest to replace them all if the cost isnt too steap but that varies.

[Legacy777]

Thanks for the feedback guys. I need to break out the meter and check the input and output voltages to the inverter. I just haven't had time and I've got crap to do tonight. I wish I could buy more time.....

[Alphius]

Enough time, not enough money.
Enough money, not enough time.

It's the age old dilemma.

[Legacy777]

That is true.

[Legacy777]

Well I couldn't really determine anything with the multimeter. I'm going to get a new inverter and see if that fixes things. If that doesn't work, I'll get a new cable.

[Legacy777]

Got the replacement inverter and the screen came up for a few seconds, got to the boot menu, and then went blank again. So either something is killing the inverters, or it's the screen. When I turn on the laptop the screen flickers for a moment and then goes blank. So I'm kind of at a loss, because when the bulb just goes out, people say you can shine a bright light on the screen to see something, but I can't see anything. So I'm curious if something more is wrong with it.

[Legacy777]

Found a cable on ebay for $9. I'm going to give that a shot, and if it doesn't work, the only thing left is the screen.