Screen turns black suddenly - OS keeps working - backlight? Dell e1705/9400 (probably hardware issue)

I have the following problem with my Dell e1705/9400.
While I was working on my computer yesterday the screen suddenly went black. However the music kept on playing. I thought this was an OS error and did a hard reset. Unfortunately after some time the screen went black once again. This time I pressed the Power Button. My OS is configured to hibernate after pressing the main switch. To my surprise the Hibernation Screen appeared and was being displayed fine. When I powered up the computer after hibernating it everything was back to normal. And then after a couple more minutes the screen once again turned black.
I tried reinstalling the drivers but this did not help. I then thought that maybe there is something wrong with my OS. I recovered my system using Norton Ghost and here is the next surprise – the screen turned off while performing the recovery operation (this was under DOS). This means that the problem is not caused by the OS or the drivers.
After examining the screen I noticed that it is not completely black. You can see the image if you look in bright light. It looks as if the backlight was not working. But after restarting the system or hibernating it everything works well again (for a while).
Any suggestions what may be causing such problems? Can this be the inverter? Or maybe the backlight tubes are worn out?
Big thanks in Advance.
Simon

 

If you can still see the display in the appropriate light, it is very likely that you have an inverter or backlight problem. These symptoms (display sometimes working, sometimes not working) are pretty common for dying backlights/inverters; I'd recommend trying to replace the inverter first. Both parts are probably pretty cheap on eBay and the like, but backlights can be a pain to replace on their own.

 

Thank you for the reply.

Can I be therefore sure that it is not a problem with the graphics card or any other part? In my country an inverter costs around 30$ and a whole new LCD panel is 120$. I am therefore wondering if maybe it would be better to buy a whole new screen. When the backlight does work then it looks fine - the image doesn't seem to be any darker. If I understand correctly the inverter is responsible for controlling the backlight? What do you recommend?

Simon

 

Hook it up to an external display. If the picture shows up normally, it's not a GPU issue.

 

Commander Wolf - thank you for the reply

I tried connecting my laptop to an external display and it works fine. This means that the GPU is not faulty. This leaves me with two elements: the inverter and the backlight. The inverter is much cheaper and I have read that a broken inverter is a common problem.

However it might happen that I'll spend 30$ on an inverter and the problem will not be fixed. I was wondering how possible is it that the backlight tubes have worn out? How many tubes are there by the way? If there is more than one then it would be strange that all of them suddenly broke down.

Currently the LCD goes black quite often. However it may happen that for 3hours nothing is wrong and then suddenly I get 3 dark screens within 20minutes. Evertime I hibernate the computer and then power it up again the screen works fine. (btw: when the computer starts hibernating does it switch the screen off and then on again to show the progress bar?)

Any advice?

Simon

 

You know, the thing is: in my experience, backlights seem to die more often than inverters, but most people claim the opposite. So maybe I'm unlucky or someone out there hates me, but I'd say there's a good chance that the backlight is ultimately the culprit.

There are some computers out there with dual backlights for outdoor viewing or whatnot, but the E1705 is not one of these. It should only have a single backlight at the bottom of the screen.

 

Hi, Thanks for all the help.

I think I'll try replacing the backlight first. In my country a new tube costs approx. 18$. Maybe I'll be lucky. If not then I will try replacing the inverter.

However today I learned something new. When I phoned a shop to ask the cost of a new tube, I was told that the motherboard may also be faulty - the part which is responsible for turning on the display. I hope this is a rare case.

The LCD has been working fine for the last 5hours - not once did it go dark. I only there was a way to distinguish a broken inverter from a broken backlight by just basing on observations.

I hope I manage to install a new tube and that I will get one which will exactly match my laptop.

Regards
Simon


EDIT:
After some further observations it seems that:

- the screen works longer (without interruptions that is) if the computer was off for some time
- the longer the screen operates the higher the probability it will go dark
- once it goes dark the chance it will work for a long period decreases

I don't know if this information is useful in any way. Perhaps it will allow to determine which part is more likely to be damaged.

 

I had the same issue with my screen it went black and i would close lid or restart computer, some one suggested disabling the ATI power management feature "POWERPLAY", by going to display properties -> settings -> advanced -> Catalyst control center ->Powerplay and uncheck the Powerplay box. This fixed my issue, my screen has not gone blank ever since.
Good luck

 

Hi.

I have an NVIDIA card so I can't try that out

I have however another question. I am currently looking for an inverter and a backlight tube. My LCD has a resolution of 1920x1200 pixels. It is possible to use spare parts from a 1440px LCD from another Dell 9400? I guess that the backlight should match but will the inverter work properly with a different screen?

Regards

 

I downloaded a small program called "MonitorOff". I launched it when the screen went dark again. Next I moved the mouse a bit to turn the screen back on and everything was fine again. Can this help identify which part is more likely to be faulty? It seems that simply turning the screen off and then on again makes it work properly again.

 

Same problem here with a inspiron 6400. Running Dell Diagnostics (F12) at reboot. Saying no problems with inverter. Can run external monitor just fine. Ordered an inverter anyway and will swap out.