Solved

Gateway PA2 LCD backlight refuses to light up - even after new inverter and new LCD

Posted on 2008-09-29
7
983 Views
Last Modified: 2013-11-17
Well,

I've replaced a lot of inverters in my day.  This Gateway laptop was displaying a very dim screen, so I reflexively ordered and installed an inverter.  The new inverter didn't fix the problem.

Instead of messing with the CCFL replacement, I decided to order a brand-new LCD.  I installed it just now, and it has the same dimness problem.  

Sometimes there is a switch that the laptop's lid depresses when it is closed.  Once, I almost replaced the inverter, but I saw a piece of junk sticking the switch down.  When I removed the junk, the backlight blinked on immediately.  

I cannot find any switch like this on the Gateway.  The keyboard bezel is smooth - no holes.  Now what?  What else could it be?  I did not replace the video cable yet, but it is in good shape and no matter how much I wiggle it, I can't even get a blink from the backlight.  With a bad cable, the problem should be intermittent.  

Anyway,  what do you think?  Is there some sort of magnet that could have fallen out of the way?  

Jason
0
Comment
Question by:compexvi
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 3
7 Comments
 
LVL 88

Accepted Solution

by:
rindi earned 500 total points
ID: 22603679
Sometimes if there are such switches they are using a reed switch (a magnetic switch which is flipped if a magnet comes close). If you have such a switch then you wouldn't see any moving parts. Anyway, those switches hardly ever break, but of course it is possible that the magnet itself has fallen off the display. But since you can see a picture I don't think there is a problem with a lid switch, it would turn off the display completely. Maybe you have a problem with the power supply or cable for the inverter.
0
 

Author Comment

by:compexvi
ID: 22605288
Thanks for the comment.  

I took apart the bottom case and found a couple of things.  The laptop has a separate video card, so I could actually replace that.  Also, the magnet in the top case seems to be in the correct spot.  

To be sure I am not missing something, do you know of any place in Windows where you can turn off a backlight?  It's a long shot, but maybe a software switch got toggled somehow.  I have played with the brightness and it is set to 100%.  

If not, I suppose it comes down to the question - should I replace the cable or the video card?  

Thanks again.
0
 
LVL 88

Expert Comment

by:rindi
ID: 22605649
You may be able to change the brightness using software, but that will be typically done using 3rd party tools from the PC manufacturer (or by using the function keys). You can always check the hardware functions by booting the PC using a LiveCD like puppy or knoppix.

http://www.puppylinux.org/
http://knoppix.net
0
Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 

Author Comment

by:compexvi
ID: 22605901
Brilliant idea on the bootable disks.  The backlight is still off, though.  Since the computer reports that the brightness is at 100% when I try to make it brighter in Windows, I am guessing the 3rd party tool that is installed is not doing anything to hamper the backlight.  

I just ordered the LCD cable, Express Mail.  I hope it will fix things.  If you have any other inspiration in the mean time, I am all ears.  

Thanks,

Jason
0
 
LVL 88

Expert Comment

by:rindi
ID: 22605933
It could also be the power that supplies the inverter, but I wouldn't know how you could test or repair that.
0
 

Author Comment

by:compexvi
ID: 22638050
So, I got the cable in and the computer still has the same problem :/
0
 

Author Comment

by:compexvi
ID: 22690050
I just told my client that he needs a new motherboard.  Thanks for the help, rindi.  I'll give you the points because you took me in a couple of directions I wouldn't have considered.

0

Featured Post

Simple, centralized multimedia control

Watch and learn to see how ATEN provided an easy and effective way for three jointly-owned pubs to control the 60 televisions located across their three venues utilizing the ATEN Control System, Modular Matrix Switch and HDBaseT extenders.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

The Samsung SSD 840 EVO and 840 EVO mSATA have a well-known problem with a drop in read performance. I first learned about this in an interesting thread here at Experts Exchange: http://www.experts-exchange.com/Hardware/Storage/Hard_Drives/Q_2852…
I'm a big fan of Windows' offline folder caching and have used it on my laptops for over a decade.  One thing I don't like about it, however, is how difficult Microsoft has made it for the cache to be moved out of the Windows folder.  Here's how to …
Finding and deleting duplicate (picture) files can be a time consuming task. My wife and I, our three kids and their families all share one dilemma: Managing our pictures. Between desktops, laptops, phones, tablets, and cameras; over the last decade…
Sometimes it takes a new vantage point, apart from our everyday security practices, to truly see our Active Directory (AD) vulnerabilities. We get used to implementing the same techniques and checking the same areas for a breach. This pattern can re…

623 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question