This dell has two OS installed Windows and Linux. I thought it would be a routine LCD inverter replacement. Dim picture? Ok I have to replace the inverter. After install the inverter I start testing and boot it up everything is ok in Linux. Now this is a weird one. I did tried to boot up in Windows everything looks ok until it logs in Windows then goes dim. I did try many times same thing. It does it in exact precise time in the boot like it is a driver or a glitch in the next step of boot. What I noticed next thing I did plug in the external monitor and both lite up like they suppose to and works as well like there is no problem at all. Unplug external monitor dim again. Boots in Linus again no problem at all. I have never seen or heard of a problem like this. Could it be a driver? But it worked before the inverter failure.

check the connection between LCD-module and motherboard.

Hi lamo. I did cross my mind, to do that, but it works flawlessly with Linux, Is Windows using different voltage in their boot and the plug would have a weak connection? That would be the only explanation in this case if it would be the plug you referring to. I would be happy to try it, but it does not make any sense. Can you explain why this p reticule problem would be there. I know welcome to laptops sometimes it can be something so stupid and it does not make any sense especially to people like me who are doing this as a hobby. But we want to learn I know I do.

Actually I made a mistake in the first post it has three OS on it Windows, Linux and Vista and by testing it I got a little confused when I typed the first tread, because I have never seen something like this. I did not think much of it Windows- Vista almost same thing. Made by same father, but we know it is different. So here it is Windows and Linus works flawlessly. It is Vista doing that weird stuff. Sorry for the confusion it may cost. Now it is the Vista driver? Maybe just because it is Vista and has some bugs and the bug kicked in?

wrapmyride, what videocard do you have in laptop? is it intel graphics or ATI graphics?

Hi Lamo
Sorry for the late answer, but I was away. It has ATI graphics, but now there is more to this story. The laptop worked for about two days with that problem two OS worked and Vista was dim, but then it happened and went dim again in all OS. Should I go ahead and replace another inverter. The one I put in was used maybe was on the way to die or is there something killing them. I did had spare Inverter then, but now I would have to buy one. The question is something killing the Inverters? Should I spend more time and money to checking, but in reality what to check?

so,you mean that in BIOS you have normal picture, but in windows you have lack of brightness?

Externally bios, Windows, Vista, Linux is working showing picture again just like a week ago did. Internally everything including bios is dim again. Now I am thinking if it could be the plug on the motherboard or a cold solder on the plug? I have seen that before on another laptop. This way it would make sense look for inverter problem or a cold solder. But that was not the case a week before. A week ago I had replaced the inverter and everything worked except Vista was dim. That time when I plug in the external monitor in Vista internal LCD lit up that was the weird part of it all. Unplug external and internal went dim again. I still think that was very weird. Then why it would work for two days only and quit again? I would like to know where to look or just order another inverter. But is it possible that something is killing the inverter.

no, it can't be cold solder, but it can be bad FL-cathode lamp in LCD module. you can only check this thing if you install another LCD module and check the picture.

Hi Lamo,
So with all the symptoms I have experienced until now it is LCD lamp. Well I will have to look for a LCD if I can borrow to try one and let you know. Are you 100% sure it is the lamp? The part I still do not understand when it worked in two systems but vista before it went completely dim. Plug and Unplug external monitor and it worked for that time. Is that time when I plug and unplug more power going to the displays and make them work? Thanks for your help Lamo

Hi Lamo.
This is a strange one I think. After all kind of messing and testing with everything possible I did left it alone for a while with all the problems that was there. I use it the way it was. Then I did run test in the dell bios about two weeks ago (just something different to do and see how that test will work and what will find). Well the test passed all no errors at all and since then everything works well. Anybody can explain this one?

dell's tests are for users. they won't show the hardware problem(except memory,cpu and video tests). and they can't identify bad LCD-lamp another thing with dell laptops(especially with inspirons 6400\9400) is with bad eeprom data in LCD-module. due to that, the brightness adjusting is unavailable, but this is not your case. so try to find another LCD module from same dell laptop and check the brightness.

Hi Lamo
Like I mentioned in post #11 everything works after running that test in bios. I know it kind doesn’t make sense. I do not need to check with another LCD. The problem went away after that test and stayed that away. It is problem free. That is what I do not understand. That test must have unlocked something in the eeprom or something. Anyway it is still working since then in all OS just like it use to before. It is been now over a month. I just would like to know what it was. And I hope it can help other members with the same problem.

the problem may repeat in the future...but i hope, everything will work good.