Compaq CQ61-231TU Display Problem

[MAXPAYNE]

I have facing an unusual problem in my laptop. Sometimes the display works, sometimes it does not. All I can see is a faint image during boot-up, when the problem arises. I have uploaded a video so that you can understand what the problem is ..

https://www.youtube.com/watch?v=2uRzFhQwkio

Unable to find the cause of this problem. Is the LCD gone ? I guess it is not as sometimes it works without no problem.

or the back-light inverter is not working ?

I connected an external monitor to its VGA output and no problem at all at this port. Display is shown perfectly.

Searching the net I didn't find any problem like this ...

How I can fix it ? I have experience of dissembling my laptop...  

[intel]

May be several reasons for this problem. First, a bad contact. Received a blow to the laptop and a small damage may have occurred. It can not be found easily. Requires expertise. If you have a chance to find and resolves problems with soldering. Second, it may be overheating graphics chip. By checking this, you can fix all the regions of cooling. For example, chip cooler or cooling grid located outside the laptop. In rare cases, the driver or programs (sometimes viruses) can cause problems. Good luck for repair.

[gmua]

Unable to find the cause of this problem. Is the LCD gone ? I guess it is not as sometimes it works without no problem.

or the back-light inverter is not working ?

How I can fix it ? I have experience of dissembling my laptop... 

You could try checking both (LCD Bulb Backlight and the Inverter Board) there are several videos on YouTube.

http://www.youtube.com/watch?v=2Yi6GNFcP3w

Good Luck...

[robotai]

It seems the backlight is working because you can see the screen with light properly. The issue looks like A/D board and LCD issue. Normally LCD has issue when seeing strip line appeared. However, if it is not occurred every time, it may means A/D board issue or some cable not well connected.

Hope this help.

[MAXPAYNE]

ya.. I have disassembled everything and reassembled it, after what  I found is everything is ok till now.. possibly there was loose connection in any part/connector. I will have a look for couple of days ... if it backs again

[FTL]

The occasional faint image during boot-up means to me that the backlight is not always working. You are just seeing the display without a backlight.

I would look at the CFL inverter(s). The CFL lamps require a big voltage hit to light, then they are scaled down to their running voltage.

When it does not light, is there a brief flash on the backlight right after power up? That indicates the start pulse is fine, but there is not enough voltage to keep it lit. That could be a weak inverter, or a tired CFL that requires more voltage to keep it lit when it is cold.

I have repaired a 46" flatscreen TV with a similar problem. The start pulse would light the CFLs, then they would go out. It would work fine if the brightness was kept high. I fixed it by overriding an analog brightness signal that was sent to the inverters.