Latitude E6500 Blank Screen

Hi Josh,

Run diagnostics to isolate the issue:

Run the diagnostics on the computer (Restart the computer by holding the" D" and power button  and wait till the LCD test completes) and let me know the status of the  screen during diagnostics. If the test fails, this could be an LCD failure.

Awaiting your response!

Rajesh,

The screen doesn't display anything, it's still just blank/black when I run the diagnostics.  When I turn on the power, there's a very faint flicker, but that's it.

My Mom has the same laptop and is planning to send it to me to upgrade the OS, so I'll do some further troubleshooting when I get it and swap out the different components to see what exactly is the problem.

I'll report back on what I find, but any other comments or suggestions are welcome.

Thanks

Josh

Hi Josh,

This can be an issue with the LCD screen itself as diagnostics did not show up the display.

Check with an external monitor for the display. As you said that you would swap the parts and check, I shall wait for your response.

Awaiting your response!

Well I got my Mom's laptop and it has a different screen.  She's got a WXGA, while I have a WUXGA screen.  So the inverter, cable, and screen are different.  I did try her screen with my laptop and it worked, so the video card is good, which I expected.

I did hook up my screen to her laptop briefly and it popped up the dell boot up logo for a second.  It did this same thing the last time I tested it with my laptop.  From the research I've done, folks with bad inverters are able to still able to see a dimly lit picture on the LCD screen.  I am not able to see anything, just a black screen.  

It's looking more like either a cable or a screen issue.  Is there any way to test the cable or the screen other than replacing it?

How does the laptop know to turn off the screen when the lid is closed?  I'm assuming there's a switch somewhere, but haven't found it.  Do you know where it's located?

Here are some pictures of the various parts if that helps.

http://main.experiencetherave.com/images/delllatitude

Thanks

Josh

Well I was testing things again and plugged in the laptop screen with the CRT monitor and the laptop screen came up and worked all the way to the boot menu selection screen and then went blank.  So it has intermittantly worked or came up a couple different occasions.  Does this sound more and more like the screen or something else?

Thanks

Josh

Just thinking out loud here....my screen has two CFFL's in it.  I'm assuming the chances of both going out at the same time is probably pretty slim.  Unless if one goes out, the other is designed/programmed to shut off as well.

If we assume that isn't the case, then that puts the problem back on the inverter or the cable.  I've verified that the video card outputs signal to my Mom's laptop screen, which also rules out any lid closing switch.

Does that sound logical?  I'll try and measure the input voltage to the inverter to see if it's receiving anything.  If it is, then I'm leaning towards the inverter.  If the inverter is not receiving a good input voltage, then I'm leaning towards the cable.

I received a new inverter on Saturday, swapped it in and the screen lit up all the way to the operating system boot menu and then went blank again.  Now upon startup the screen flickers for a split second and goes blank.  It does this with both the new and old inverter.  

I still find it hard to believe both lamps in the screen went bad at the same time, but anything's possible.  I'm down to the either the cable or the screen.

Any recommendations?

Thanks

Josh

Well the plot thickens....I ended up trying a new cable and it made no difference.  I finally was able to see that the LCD was still working, so knew it was the backlight that went out.

I bought a "good" used working LCD on ebay, put it in last night, and it worked fine, no problems.  I open the lid on my laptop this morning, screen turns on, I open my email, and the screen goes black.  I checked and again, the LCD is still working, the backlight is out.

What are the chances I got a second screen where the backlight went out?  Or could there be something that's causing the backlight's to fry?  

Thanks

Josh

Hi Jorrit,

Yeah, your screen "failure" sounds very similar to mine.  The original screen worked fine, the laptop power settings turned the screen off, I woke it up, and the screen flashed on for a second or two and then went black.  The second screen I got kind of did the same thing.  The laptop turned the screen off over night, I woke it up in the morning, the screen came on for a few minutes and then went blank.  If I turned the laptop completely off for a while, the screen would work for a 30-60 minutes and then would die.

I sent the screen I bought back, and the guy is supposed to be sending me another one.  I haven't checked to see when I will get it, but hopefully it will be soon.  If this screen doesn't work or does the same thing, then I would tend to agree with you that something else isn't right.  The odd thing though is that the video card works to send the signal to an external monitor.  Plus, when I had my Mom's laptop, I was able to power her WXGA screen with my video card without any issues.  I didn't leave it run for an extended period of time, but the screen booted up fine and worked when I was testing things.

My only other thought if the second screen dies or doesn't work is that the WUXGA screens are more tempermental and there's something else wrong.  At that point....it's probably not worth trying to fix the laptop as I don't want to keep chasing my tail, so to speak.

I'll be sure to update this thread when I get the second screen.

Thanks
Josh

Hi,

I was reading your posts and it seems that I have the same problem. I also have a E6500 with a WUXGA screen (2 CCFL's). My first (and most obvious) guess was a broken inverter board. I replaced the inverter board with a new one and it worked again, for a little while. After 15 minutes or so leaving it unattended the screen went black again, and never went back on again.

My next guess was that one of the CCFL's is damaged. Most inverter boards are protected to switch off if one of the CCFL tubes is broken because then there will be too much current generated on the board. But if I read your findings that swapping a whole LCD panel (so also the ccfl) did not work, I am starting to think the problem may be near the motherboard (graphics card, power supply, cable?).

I am not sure what my next step will be. I don't want to buy a new LCD panel ($100) without knowing if that will be the solution. I am looking for a way to see if my new inverter board is still functioning and if my LCD panel will work on another laptop but I don't have another Dell laptop here.

I will post here if I get any closer to fixing this problem, I hope that you do the same.

Thanks

Jorrit 

Hi Josh,

I noticed something today. When I turned on my laptop the screen was working again. My battery was about 20% no external monitor or power cord was connected. The screen worked even in Windows, although it was a bit dim. The moment I attached the power cord the screen brightness went up for a few seconds and then off.

This makes me think again that it has something to do with the ccfl and/or inverter. It seems that the board cannot supply the full power and shuts itself down for safety.

I might try a new ccfl or test the ccfl tube with a separate inverter board. Now I have to figure out where and which size of ccfl I must order.

I'll keep you posted.

Jorrit

Jorrit,

Thanks for the comments/feedback.  The guy I bought the used screen from that didn't work....or stay working....said he's got that screen up and running and has been for 3 days.  So I'm back to square one again....unless he's feeding me a line of BS, which I don't think.

I've tried a different inverter and cable and got the same results.  I'll try seeing if it works just on battery power.  I'm not sure what else could be causing this.  I suppose the video card could be working with the external monitor, but not work with the screen.

Let me know what you find out and I'll do the same.

Thanks

Josh

No go with my old screen.....I get nothing from it.

Ok, just tried it again, rebooted instead of hibernating with the power supply unplugged, and the screen came up, I'm in windows.  So I guess we'll see how long it stays up.  So it seems like my issue is identical to yours.

Have an update this morning for you.  I think the issue is related to the screen brightness, not necessarily whether the power cord is plugged in.  Since the brightness dims when just on batteries, this is why I'm thinking that.  I turned down the brightness from full bright when plugged in, and even with the screen "sleeping" over night, it came back up in the morning.  I then turned the brightness all the way up again to see what would happen.  The screen worked fine for a while, I ate breakfast, the screen went to sleep & turned off, I woke it up, it worked for a few minutes and then the backlight turned off.  I turned the laptop off, unplugged the power cord so it would boot up without being on full brightness.  The screen came up and booted up normally.  

The one thing I noticed on boot up was the screen flickered and got bright for a second or two and then went back to the normal brightness.  Not sure if that is attributed to the lamp or the inverter.  I'm going to try an extended test with the back light brightness turned down a notch or two from full bright and see if it works like this.

Any thoughts on what these symptoms point to as the actual problem?

Thanks

Josh