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Main => Everything Else => Topic started by: somunny on March 26, 2007, 03:24:53 pm

Title: Laptop problems... Updated
Post by: somunny on March 26, 2007, 03:24:53 pm
Naturally, since I'm off for two weeks and I have a bunch of photos to go through, my laptop decided to crap out.

When I boot it up the screen is extremely dark.  I can just barely make  out what is on the screen.  It as if the light was turned off inside the display or something.  I'm not really sure how these things are put together.  :dunno

Any ideas? 
Title: Re: Laptop problems...
Post by: ChadTower on March 26, 2007, 03:26:24 pm

Is it the LCD or the OS?  First guess from that description is that your LCD backlight is dead.
Title: Re: Laptop problems...
Post by: shardian on March 26, 2007, 03:30:09 pm
I will second Chad. Probably something blew on the backlight inverter board.
Title: Re: Laptop problems...
Post by: AlanS17 on March 26, 2007, 05:33:50 pm
You could try the obvious first, and then look for a more obscure (though completely possible)  problem like hardware failure. Most laptops have function key combinations that control brightness and contrast. Have you tried messing around with those?
Title: Re: Laptop problems...
Post by: USSEnterprise on March 26, 2007, 05:44:55 pm
Did you try an external monitor yet?
Title: Re: Laptop problems...
Post by: somunny on March 26, 2007, 05:59:08 pm
You could try the obvious first, and then look for a more obscure (though completely possible)  problem like hardware failure. Most laptops have function key combinations that control brightness and contrast. Have you tried messing around with those?

Tried that.  There's a couple of F keys that do brightness and contrast.  No luck.

Did you try an external monitor yet?

Haven't tried this yet.  It's on my list.


Is it the LCD or the OS?  First guess from that description is that your LCD backlight is dead.
I will second Chad. Probably something blew on the backlight inverter board.

This definitely sounds plausible.  I'm leery about pulling it apart, though.  This thing looks like it would come apart easily but going back together, well...  Do you think this is an expensive fix?

Title: Re: Laptop problems...
Post by: USSEnterprise on March 26, 2007, 06:01:38 pm
well, not knowing exactly what the problem is, its hard to tell. Could be a bad video driver on the logic board, could be a bad inverter or backlight. Could be a lot of things.
Title: Re: Laptop problems...
Post by: boykster on March 27, 2007, 01:41:43 am
well, not knowing exactly what the problem is, its hard to tell. Could be a bad video driver on the logic board, could be a bad inverter or backlight. Could be a lot of things.

If you can make out the screen, but the display doesn't "light up" so to speak, it's definately somewhere in the backlight.  It could be:

- the switch that compresses when you close the laptop lid
- the inverter board that converts low voltage DC to high voltage AC to power the CCFL light
- the CCFL backlight bulb itself
- a control circuit somewhere else, but unlikely here

Depending on the age of the laptop, it might be worthwhile to take it to a repair place, or to open it up and check it out for yourself.  if you can verify that it's either the switch or the inverter, you <might> be able to repair it yourself.  If it's the CCFL backlight, I doubt it's user serviceable.
Title: Re: Laptop problems...
Post by: ChadTower on March 27, 2007, 09:00:46 am

If it is the backlight bulb, is that a case for replacing the bulb or the whole screen?
Title: Re: Laptop problems...
Post by: boykster on March 28, 2007, 01:04:21 am

If it is the backlight bulb, is that a case for replacing the bulb or the whole screen?

generally it requires replacing the entire LCD screen.  With most recent LCD panels, the backlight is integrated into the sealed LCD package and is not a replaceable part.  The last time I messed around with laptop type LCD panels was about 4 years ago, and at that time they were ALL integrated sealed units that were not user serviceable.  NO way to replace the backlight.

If you're inclined, disassemble the laptop and try to find the manufacturer and part number on the LCD screen.  NOT the laptop model or manufacturer, but the manufacturer and part number of the actual panel.  There are several sites online (as well as ebay) that source replacement panels, but usually you need an EXACT replacement part as there isn't a standard connector for these things.
Title: Re: Laptop problems...
Post by: somunny on March 29, 2007, 02:58:30 pm

If you're inclined, disassemble the laptop and try to find the manufacturer and part number on the LCD screen.  NOT the laptop model or manufacturer, but the manufacturer and part number of the actual panel.  There are several sites online (as well as ebay) that source replacement panels, but usually you need an EXACT replacement part as there isn't a standard connector for these things.

Well, the output is good to an external monitor so I'm going to give it a go and take apart the lcd housing.  Stay tuned...
Title: Re: Laptop problems...
Post by: boykster on March 30, 2007, 12:15:06 am
First thing I would check is the inverter.  It will be a small circuit board with a set of wires (probably 2) coming in and wires leaving it.  The input will be 5 or 12V DC, and the output will be 1000V+ AC (very low amperage).  Check both sides of the inverter to ensure that DC voltage is coming in, and that AC voltage is going out.  You'll need a multimeter to check that.

If that's good to go, then the backlight is probably suspect.  If the AC side of the inverter isn't powered, then you need a new inverter.  If the DC side isn't powered, then you've got a problem further upstream.

Title: Re: Laptop problems... Updated
Post by: somunny on April 21, 2007, 10:58:01 am
Well, I ended up sending the laptop back to the manufacturer to have them take a look at it.  They called me last week and told me it was a motherboard problem.  The tech explained that they didn't stock that model motherboard anymore and that it would be $400 to refurbish the old one.  I had them send it back unrepaired figuring I could just hook it up to an external monitor (which I had done successfully before I sent it off).

Just got it back yesterday and now it mysteriously won't power on at all.  Sabotage maybe?  The thing was working normally excpt for the display when I sent it to them.
Title: Re: Laptop problems... Updated
Post by: BobA on April 21, 2007, 04:18:27 pm
Link to monitor repair thread and laptop info link added at end.

link to thread (http://forum.arcadecontrols.com/index.php?topic=65708.0)
Title: Re: Laptop problems... Updated
Post by: shardian on April 22, 2007, 12:26:38 am
Well, I ended up sending the laptop back to the manufacturer to have them take a look at it.  They called me last week and told me it was a motherboard problem.  The tech explained that they didn't stock that model motherboard anymore and that it would be $400 to refurbish the old one.  I had them send it back unrepaired figuring I could just hook it up to an external monitor (which I had done successfully before I sent it off).

Just got it back yesterday and now it mysteriously won't power on at all.  Sabotage maybe?  The thing was working normally excpt for the display when I sent it to them.

And that is why I will never send another product of mine to the manufacturer for  repair unless absolutely necessary. Once upon a time, I had a Toshiba laptop and it brokded quite often. No matter what the repair (one time it was a hinge on the modem port) they ALWAYS reformatted the hard drive. WTF?? When they did fix it, they put defective parts in it. How can a hard drive fail every 2 or three months with only sporadic use??

I talked to a guy once that shipped a Sony Camera in for repair. It had an aftermarket lens on it and a memory card inside. Guess what? The lens or the memory card never came back and the repair company denied, denied, denied. That is why I decided to live with my Sony camera and its intermittent ccd fault.

Long Story short, they will deny any wrongdoing and you are just screwed up the pooter buddy.
Title: Re: Laptop problems... Updated
Post by: boykster on April 22, 2007, 01:16:49 am
that sucks.....sorry to hear that your laptop is worse off than before you sent it in.  But $400 is a ripoff to fix it, you can get a perfectly decent new laptop for $500 if you look....