Need help fixing notebook backlight!!!!!

Need help fixing notebook backlight!!!!!

My Compaq (yes I know Compaq sucks) laptop is now 13 months old (one month out of warranty Damn it) and out of the blue the screen is now dark. I did a search and I think the problem is the backlight. If I shine a bright light on the screen I can see what I'm doing (kind of, its really hard to see the cursor). Interestingly, if I push on the little flexible button on the top of the laptop (the one that that senses when the screen is folded down) the screen will flash very briefly with full light.

My guess is there is some kind of loose connection between the backlight and the board. Or possibly the sensor that shuts off the screen when folded flat has stuck or jammed.

I am a little hesitant to crack the computer open but I figure what do I have to lose. If anyone here can give me any help on this I would be eternally grateful. Especially if you have experienced this problem yourself and have some "pearls of wisdom" that might keep me from screwing things up royally.

BTW this is a Compaq R3000 AMD 64 3200+, Windows XP, 512 MB DDR RAM, 60G HD, 15.4 widescreen LCD.

 

If you need to use it urgently you could plug in a monitor for now.

In my personal opinion it sounds like a connection problem with the prong that switches the screen on and off as you open and close it.

 

I've been through this before with 2 laptop... same exact problem. The first laptop I had was still under warranty so I went through the always pain in the ass Dell support and EVENTUALLY reached a point where they actually sent a guy out to my house and coordinated a time when I would be there too and he replaced my screen... all for free... all under warranty... so sounds like you may be under warranty still as well and you should contact your Compaq support.

However, should you be the kind of person who likes to dabble with computers and what not I also have a solution that involves no customer support but about 30 bucks of your money.

The backlight is very rarely the problem in these cases. This is because the backlight is nothing fancier than a standard florenscent light bulb (just REALLY small in comparison to the ones we're used to) therefore, the bulb as an incredible hours life and rarely will this burn out.

In the second laptop I fixed the warranty expired and I did some research and found out that 90% of the time the problem is your Power Inverter went bad on the back of the LCD. A new power inverter costs right around 30 bucks depending on the make and model etc. just googling around should find you the right Inverter Board

Replacing the Inverter board is incredibly easy... simply take apart the screen by unscrewing all screws you see on the screen part (some screws may be hidden behind rubber stoppers) and then there's more screws on the sides of the screen.. once these are taken off you can access the back of the screen... usually taped to the back of the screen you'll find your power inverter and replacing it simply involves unplugging and untaping the old one and replugging and taping in the new one... piece of cake! Look up on-line your laptop and how to remove the LCD for more detailed directions and precautions.

Hope that helps... Let me know if you have any other problems or questions and how it goes.

 

Well, AFAIK the warrenty expired last month. I had been debating signing up for the extended warrenty, but I figuered for $200 for two more years you can fix a lot of problems yourself. Plus, you always hope it won't happen to you.

Thanks for the reply MBlock. I do have a question though. Could you still see the text on the dark screen if you shined a bright light on it? If this is a power inverter problem would the display still function except for the backlight? If this is the power inverter, it would be great as this sounds easy to fix.

Anybody have any idea if the prong that senses when the shell is closed can cause this problem. Because jiggling this prong will make it work for a fraction of a second before it darkens again.

 

Update,

Well while I was fiddeling with the laptop last night I gave the screen closing sensing prong another wiggle and the screen came on and stayed on instead of flashing on and off like it had been. So, it is currently working, but who knows how long. If it shuts off again, I would still like some feedback on how I might fix this. So, if anyone here has dealt with this I would love to hear from you.
Thanks,
Steve

 

Hmm... I am interested in seeing how long it stays on after you've gotten it to stay by wigling the prong.... because it's true that could very well be a problem... the contact the button makes when shut could be sticky... I know on a Dell Laptop you can easily remove the top plastic just above the keyboard and where the power button is to see inside a little bit... I would explore around on yours and see if you can clean the contact somehow with like a pencil eraser or something to clean it off.

As far as your other questions. Yes even if the power inverter goes bad you still see all the data on the screen just very very dark. This is because the cable from the motherboard to your screen takes two paths. The first path if you ever see your cable (and you will if it comes down to replacing your power inverter) is a much wider part of the cable and this carries all the instructions of what to put on the screen where and which liquid crystals to stimulate where... The second part of the cable is considerably narrower and this part plugs straight into the power inverter. This acts as a form of control for the power inverter and dictates the strength or dim of the backlight and how much power needs to be inverted through the board.

Therefore if the power inverter goes bad you loose your backlight because the control signals being sent are not being interpretted through the board. But the wider part of the cable is still sending and stimulating the crystals on the screen, hence you can still see the display.


So, should your display go out again... try the FREE route of tampering with the prong and seeing if that yields anything... if it does not than start looking around for a reputable website that sells your power inverter (you may need to look at your power inverter and start googling to find it or just search for "*your computer name* power inverter" and feel it out and order it up.. I lucked out and found a website SOLEY Dedicated to selling NOTHING but spare parts for Dell laptops.. it was amazing lol.

Keep in mind there's still a very SLIM chance replacing the power inverter will not fix it and it could truely be the backlight. But as I said in my last post 90-95% of the time it's the power inverter and as you'll find the power inverter is MUCH cheaper and 100% easier to replace SO... odds and funds in your favor... do the inverter first because as far as I know there's no easy way to troubleshoot and determine if it's the board or the light. Good luck! Keep any questions coming

 

Well, the fix lasted all of about 2 days. The backlight went out again last night. So, cover me guys, I'm goin' in. If it does seem to be the prong I'll let you know.
Also, thanks for taking the time to respond MBlock. I did a search for the specific power inverter I need and it seems to be going for $99 at various sites. Ouch, that is more than I was counting on.
Also since the problem seems to be intermittent, I will also take off the back of the screen and try to make sure the connection to the inverter is tight as well.
Thanks for your help.

Steve

 

Re: Need help fixing notebook !Need help in dissection

Wow, how do I even get to the prong?
I opened up the back of the laptop and after removing about a hundred little screws was able to remove the bottom plate. However, all this did was expose the underside of the MOBO. It appears that to get to where the prong attaches I have to remove the fans and heatsink and CPU. Do I really need to do this? Even then it seems like I need access to the other side of the MOBO. Is there a way to remove the top panels of the laptop to get access to this area. I did not want to start randomly applying force to see if the panels would pop off. Also, how do I gain access to the inside of the LCD screen to check the power inverter connection? Or, (forgive my ignorence) is this even in the screen part of the clamshell? I need some help from someone who has dissected their notebook before to give me a little guidance. I can't seem to find a blueprint for how things attach anywhere on web.

I feel quite comfortable working on the inside of my desktop, but it is so hard to see how things simply are attached inside of the notebook. Please help!!!!!!!

 

This is on taking apart toshiba laptops maybe this will help
http://www.irisvista.com/tech/index.htm

 

Re: Need help fixing notebook backlight!!!!!Update, fixed

I found a great deal on a LCD power inverter and decided to go for it. I pretty much had disassembled the entire laptop to check connections and still the LCD was dark.
So, once the inverter arrived, it took about 5 min to dissasemble the screen again, install the new inverter and reassemble.
I then reconnected the power, fired it up and Viola!!!!! I now have a fully funtional laptop once more.

Thanks to everyone who gave advice here especially MBlock .

 

I am having the very same problem did you get yours repaired and how????