Sign in with
Sign up | Sign in
Your question

How to tell if it is my backlight or inverter

Last response: in Laptops & Notebooks
Share
June 17, 2010 4:57:11 AM

Help please!

I have Compaq Presario V2110US Widescreen. Yesterday, while surfing the net, the screen just went black. I tried to restart and the full display came up for a several seconds and looked normal. I thought I had a virus so I tried to go into Safe Mode because I thought maybe it was a virus but display went dark again before I could get there. So it is not a virus. Hardrive and fan are both working.

So, this is what happens - when I turn it on I get the full screen for a few second than it goes black, but if I look closely or with a flashlight I can see my desktop display.

If I press the hiberate toggle button, on the upper left hand corner of the base, the display will come up for a second, go black again and than go into standby/hiberate (and I can see the display with flashlight like before). If I press the button to unhiberate, than I get the full lit display again for a few seconds and than black again.

If the display does light up fully on occasion, it is my inverter or my backlight. Seems like the light is still working or it would never light up at all right?

I want to repair myself (I have replaced the fan in this before and I am in IT) because I can't afford to bring it in and heard it can get expensive. But I want to make sure I get the proper part - either the inverter or the backlight. (they are separate things right?)

Any bets on which part it really is? My guess is the inverter.

thanks much in advance,
Kimberly

More about : backlight inverter

a b D Laptop
June 17, 2010 6:45:23 AM

kgarbac said:
Help please!


If the display does light up fully on occasion, it is my inverter or my backlight. Seems like the light is still working or it would never light up at all right?

I want to repair myself (I have replaced the fan in this before and I am in IT) because I can't afford to bring it in and heard it can get expensive. But I want to make sure I get the proper part - either the inverter or the backlight. (they are separate things right?)

Any bets on which part it really is? My guess is the inverter.

thanks much in advance,
Kimberly


[#0005ff]I think you're right but before buying anything, I suggest checking the connections. Some inverter leads can get trapped in th elid opening and the slightest movement can pull one or the other from the invertor connectors. The same is less likely to the backlight and it's also less likely, in my experience, to have failed. Download your manual from the maker's website before taking the bezel off the screen and use a needle to pull the little rubber plugs out which conceal the screws you need to withdraw. [/#000ff]
m
0
l
June 17, 2010 1:02:21 PM

If sagas answer does not work replace the inverter 1st as it will be alot cheaper, I don't think there will be a way to tell without trying it.
m
0
l
Related resources
June 17, 2010 4:26:17 PM

Thanks so much simon12 and saga lout!

saga lout,
I think I know how to take it apart and I know where the screws are at. I found something online that shows the steps but I will look for the manual as well. I have my user manual that came with the laptop - don't think this stuff in there though! :) 

Are the inverter leads in the screen or in the base? From the inverter pics I have looked at, I am guessing they are the "connectors" at the end of the inverter piece. Just clarifying what I should check.

Also is it best to take the base apart to disconnect it from the screen first or is it really not necessary?

Simon12,

This is what I am thinking too. So far I have only found two places online that have my inverter - not even Ebay has it - has the backlight though! :) 
m
0
l
June 17, 2010 5:08:25 PM

I haven't taken a laptop apart for years but all older laptops you can do it all by removing the screen bezel.
m
0
l
a b D Laptop
June 17, 2010 6:27:41 PM

kgarbac said:
Thanks so much simon12 and saga lout!

saga lout,
I think I know how to take it apart and I know where the screws are at. I found something online that shows the steps but I will look for the manual as well. I have my user manual that came with the laptop - don't think this stuff in there though! :) 

Are the inverter leads in the screen or in the base? From the inverter pics I have looked at, I am guessing they are the "connectors" at the end of the inverter piece. Just clarifying what I should check.

Also is it best to take the base apart to disconnect it from the screen first or is it really not necessary?

Simon12,

This is what I am thinking too. So far I have only found two places online that have my inverter - not even Ebay has it - has the backlight though! :) 




Whenever I've had to replace a screen or inverter, the latter has been behind the bottom of the bezel, underneath the edge of the screen.

m
0
l
June 18, 2010 1:00:57 AM

Hi guys.

Ok, i took it apart checked the connectors. It looked OK. But I reconnected the one with the pink wire on the right side (which goes to the backlight right?) I couldn't figure out how to get the let side one out which goes to the video cable so I just checked it and left it alone.

The instructions I used were these here: http://www.screentekinc.com/lcd-removal-instructions_en...

So, the problem is not fixed but now my colors are all screwed up! wah! It looks like an abstract black and white painting and I can't see my desktop behind it (probably because the colors are screwy.

The instructions above required me to removed the video cable and I think I put it back in correctly - but I am guessing that is why my colors are screwy now. NO display comes up just black and white color.

I tried to be careful but it I mess something or should I go back and reatttach the video cable.

the bevel and the screws on the hinges were especially difficult but now I am wondering whether or not I really need to do that. grrr..

So I think the inverter is bad but any suggesting on what happen to my display and why does it look like screwy painting now?

Thanks, Kimberly
m
0
l
a b D Laptop
June 18, 2010 6:47:36 AM

kgarbac said:
Hi guys.

the bevel and the screws on the hinges were especially difficult but now I am wondering whether or not I really need to do that. grrr..

So I think the inverter is bad but any suggesting on what happen to my display and why does it look like screwy painting now?

Thanks, Kimberly



[#0005ff]First thing to do now is confirm the screen is working by outputting to a PC monitor. If the picture is good there, no harm has come to graphics which, I believe, could have happened if wires were crossed.

If you get a clear picture on that other screen, go back in and check the connections. The plugs on both ends of the inverter will only go in one way - Murphy's Law of Aircraft Engineering applies to most computer parts and that says "if something could be put in the wrong way around, it will be". The difficult one is the ribbon cable to the back of the screen - did you touch that one? If that's slightly skewed it could explain the Picasso effect you're seeing.
[/#000ff]
m
0
l
June 18, 2010 5:06:48 PM

thaks saga lout!

Yes, in the instructions I used it said to disconnect the video cable. I think that is what did it maybe. I really couldn't get at the inverter connections without doing that. The inverter was in kinda crooked and when I pieced everything back to together I put in back in better so now I can get at it without taking the screen off the hinges.

Also right after I took the bevel off (it was hard to get off - I tried to be careful but I honestly had to pry some of it loose with a flat head), the front of my LCD screen had dark spots under it (like it had gotten water under it) and they are still there - they were not there before

Yesterday night I plugged my mom's VGA montior into my laptop, when I turned it on I got my initial startup come up which I recognize and than Windows tried to load but than the VGA montior didn't show anything else just black and it went in to sleep mode- I tried several times and it kept doing this. I am wondering if it because the graphics are screwed up now. I wish I had done it the night before - but I didn't think I had the right connector.

I made sure that I put the right inventer plug back in right (one side had little dots on the plug so it was easy.

I am thinking it is because I messed with the video cable (the ribbon). I guess I will have to retry and see but I think I am going to get a new laptop (cheap one) for now but keep working on this too.

How easy it to mess up the LCD? It was hard not to remove those hinge screws without having a good hold on the screen (even that white part on the back that says "Do not touch White tap" - it is almost impossible NOT to touch it if you need to remove the screws from the hinges).

Thanks so much for helping me. I'll keep trying. :)  I do think I need I new invertor though but I got to get the graphics back to normal first. I am guessing that is why I can't see my desktop in the background anymore even with a flashlight.



m
0
l
a b D Laptop
June 18, 2010 6:48:59 PM

kgarbac said:

How easy it to mess up the LCD? It was hard not to remove those hinge screws without having a good hold on the screen (even that white part on the back that says "Do not touch White tap" - it is almost impossible NOT to touch it if you need to remove the screws from the hinges).

Thanks so much for helping me. I'll keep trying. :)  I do think I need I new invertor though but I got to get the graphics back to normal first. I am guessing that is why I can't see my desktop in the background anymore even with a flashlight.



I wish now that I'd thought to mention that there's a delicate area around the back and all along the top of the screen - I hope you didn't handle that area too roughly. If there were traces of moisture it could explain a thing or two. I've had instances where the screws had almost been rusted in and I've been told just one night for the laptop in the boot of a car in cold weather could cause that. However if that moisture seems to be inside the screen casing that's unlikely to be the cause but might indicate what's wrong with your display.


m
0
l
November 20, 2013 4:08:58 AM

so u guys still didn't get the answer >.< am having the same problem with my pc's monitor but its not the screwy colours but the first problem he mentioned
m
0
l
December 28, 2013 10:47:33 AM

Try what I (accidentally) did: connect your laptop to an external monitor, and with its aid activate the laptop's cammera. Only this turned the backlight on again in my Toshiba Satellite L45. I hope it works on your machine as well!

m
0
l
!