The Teej Posted January 30, 2011 Share Posted January 30, 2011 Hey all. I've recently dug out this laptop from the depths of my old bedroom and decided to get it back up and running again. I've got it done successfully - I'm typing on it in fact! However, there's an issue that has persisted for the past few years and I'm starting to run out of ideas. Basically, the screen keeps dimming on and off. In the same manner that when a laptop goes to battery from AC, the screen dims, it keeps doing this but persistently. I have tried the following: Switching from XP to Ubuntu Replacing the battery Replacing the power supply Taking the battery out and running purely on AC power Running purely on battery power (laptop dies instantly) Trying an alternative power supply which 100% works (same, vdc, mAh, tip size, etc) Short of taking apart the whole laptop (which, I'm not -entirely- sure how to accomplish with this particular model) and resoldering the power socket on the laptop I'm running out of ideas on how to fix this issue. Even when running purely on AC power, it -still- dims on and off like its being connected on and off, even though this is impossible as the laptop would die instantly if that was happening. I've also gone into power management settings on Ubuntu to turn off background dimming and it's ignoring that completely (even after making that default settings as a superuser). So... yeah. I figured if it was the light going out it would have gone by now as I've had this issue for years. The battery light also occasionally flashes as if the battery is on low power (even with no battery inside!). I'm calling upon the collective expertise of the Neowin community to give me some insight on how to fix this one as I have no clue. So, please help me! Many thanks in advance. Link to comment Share on other sites More sharing options...
Frylock86 Posted January 30, 2011 Share Posted January 30, 2011 Are your power settings set to dim the screen? Link to comment Share on other sites More sharing options...
The Teej Posted January 30, 2011 Author Share Posted January 30, 2011 Are your power settings set to dim the screen? No, completely off in that regard. Link to comment Share on other sites More sharing options...
dragon2611 Posted January 30, 2011 Share Posted January 30, 2011 Could be a fault with either the back light or the inverter that drives it. Link to comment Share on other sites More sharing options...
The Teej Posted January 30, 2011 Author Share Posted January 30, 2011 Could be a fault with either the back light or the inverter that drives it. Well if it's that I'm completely ****ed, I'm guessing that's gonna be a bomb and a half to replace or get repaired? Link to comment Share on other sites More sharing options...
Frylock86 Posted January 30, 2011 Share Posted January 30, 2011 How old is the machine? You might be just better off buying a new one. Link to comment Share on other sites More sharing options...
dragon2611 Posted January 31, 2011 Share Posted January 31, 2011 (edited) Well if it's that I'm completely ****ed, I'm guessing that's gonna be a bomb and a half to replace or get repaired? Not sure I've only had one ever fail on me and Luckly that Laptop was in warranty so it got repaired at the manufacturers cost. If you're good at taking laptops apart and can actually get hold of one the inverter can be replaced. Edit: Just had another thought, does the laptop have one of those ambient light sensors that's supposed to automatically adjust the brightness based on the ambient light levels? I've seen those constantly adjust the brightness between bright and dim in the presence of some types of fluorescent lighting. Usually if it has one there will be some key combination or maybe a BIOS setting to disable it and set a fixed brightness. Edited January 31, 2011 by dragon2611 Link to comment Share on other sites More sharing options...
The Teej Posted January 31, 2011 Author Share Posted January 31, 2011 How old is the machine? You might be just better off buying a new one. 6 years old. I was gonna dump another gig of RAM in there and have it for my bedroom for playing movies in there and stuff. Not sure I've only had one ever fail on me and Luckly that Laptop was in warranty so it got repaired at the manufacturers cost. If you're good at taking laptops apart and can actually get hold of one the inverter can be replaced. Edit: Just had another thought, does the laptop have one of those ambient light sensors that's supposed to automatically adjust the brightness based on the ambient light levels? I've seen those constantly adjust the brightness between bright and dim in the presence of some types of fluorescent lighting. Usually if it has one there will be some key combination or maybe a BIOS setting to disable it and set a fixed brightness. I've never taken one apart, but I suppose I could give it a try :p This laptop is so old it probably doesn't even understand the concept of ambient light sensors haha. I will look around in the BIOS though to see what I can mess around with (you never know!) Thanks for your suggestions so far guys! If anyone has any more though please give me a shout :) Link to comment Share on other sites More sharing options...
voidpharoh Posted February 2, 2011 Share Posted February 2, 2011 I've seen many laptops that have options in the BIOS/CMOS in regards to power settings & display brightness. Some of the older laptops would ignore the OS power settings in favor of what was set in the BIOS/CMOS. I would say take a look there and see if you can find something that corresponds to display dimming in the settings. Link to comment Share on other sites More sharing options...
Detection Posted February 2, 2011 Share Posted February 2, 2011 I also say this is an inverter / screen issue - more likely to be the inverter as this is the little piece of circuitry that powers the backlamp You will be able to pick one up on eBay for a few quid, take the plastics off from around the screen and replace it (Just a couple wires clip in each end) Id say the cheapest test you can do without replacing the screen / mainboard Link to comment Share on other sites More sharing options...
Recommended Posts