LCD screen went dim and I noticed a high pitched noise coming from it
I have a Toshiba P35-S611 (bought a little over a year ago and warranty done). I am having similar LCD problems like a few others where the screen has gone dim. It started one day when for some reason it went dim and I noticed a high pitched noise coming from it. I turned off the laptop immediately. I waited a while then turned it on and it looked fine, but then went dim again the noise came back. Now I can’t even turn it on, just starts dim with sound. I am pretty sure it has something to do with the screen. When I tried playing around with the little knob (the one that when you close the screen turns the screen off), I found that whenever I press it the screen goes black (even more so ) and the noise stops. If I rapidly press the knob I can even sometimes get the screen to flicker to normal brightness. I tried plugging it to a monitor/external LCD and it works fine with no noise problem. While I can get by with using a monitor for now, I still need a laptop and not a fancy desktop, also my screen is a 17” (true bright) and no external screen will give the same resolution quality. I am thinking it might have something to do with the converter but haven’t heard any talk about a high pitched noise also. When I shut off the screen (hibernate or sleep by closing the lid) the noise stops, and it works with an external.
While scanning through the internet I ran across a forum where a person said that high pitched noises usually come from a part of the laptop that is either getting to much or not enough power. I am not sure if this would help, but I am thinking, there might be a connection. The screen isn’t working but the inverter/converter (whatever it is called) connecting the screen to the laptop is still getting the full power supply.
I think that you might have a faulty FL inverter board. Take a look at the laptop display assembly diagram. The backlight bulb lights up when it’s getting enough power form the FL inverter board. The inverter board acts as a power supply for the backlight bulb, it converts low voltage DC power to high voltage AC power. If there is something wrong with the inverter board, the backlight will not light up. I think the high pitch noise is coming from the FL inverter board and I would try replacing this board first. Here’s guide for taking apart the display assembly on a Satellite A65 laptop. It’s not for your laptop, but all steps should be pretty similar. If you follow steps 1-6 you should be able to replace the inverter board yourself. If you are not confident, take the laptop to a repair shop because you can damage it.
BTW, when you have a faulty display inverter board, you still should be able to see a very faint image on the laptop screen. Can you?
August 17th, 2010 at 11:04 am
Hi, I believe this problem MAY be an inverter problem but i am not sure. My laptop has been flickering on and off at times ( flickering is white ). I think it may be loose cable due to compressed air? But for now, I am not so sure if it is a hardware problem or a driver problem.. I have no idea on what is causing this flickering nor any way of finding out. Please help.
February 17th, 2009 at 6:14 am
Hi. I have a Dell Inspiron 1501 and the LCD screen is going dim, however it’s only the left side, not the entire screen.
Also there have been times in the past few weeks when the battery is unplugged the screen turned off and would not turn back on when it was plugged back in. (yes I did check the settings to make sure that wasn’t an issue, it’s not)
Also anytime the battery is unplugged there is a high pitched whining sound.
Any help would be great, thanks.
September 15th, 2008 at 5:59 am
Hi. I have a HP Pavilion DV1000, I had a bad inverter so I replaced it, it works fine but only if the AC adapter is plugged in, shortly after it’s removed the screen goes dim, I also may have a bad battery because even charged at 100% it dies in a few mins. Coud that be the problem?
August 27th, 2008 at 10:19 am
Help I am having the same problem and I have a question:
I also have a Dell Inspiron 5150… and my screen is extremely dim. In the right light and at the right angle, I can see the screen. It never flashes to full brightness at start up. However I am wondering if something else might be wrong because the laptop will not operate on an external monitor. What do you think? Is this the inverter or something else?
June 27th, 2008 at 12:21 am
Thank a lot. I am planning to go with the full display panels since they are much less likely to break in transport and are not that much more.
June 25th, 2008 at 10:42 pm
Robert,
It’s not easy to replace the CCFL bulb. It’s buried deep inside the LCD screen and you can easily damage the screen during the disassembly process. I would consider buying the whole display panel witch includes LCD screen, inverter and video cable, check out these display panels.
Not sure about the voltage but you must get the correct length or it will not fit into the screen. I have a couple of different backlights with different connectors I removed from cracked screens. I use these backlights to test all laptops regardless the model and the brand, they always work fine. I guess any laptop CCFL bulb will fork fine with your screen as long as it has correct length. Just a guess.