Hey guys, I recently installed a new screen on my girlfriend's Acer 6935G laptop after the original cracked; a seemingly common fault. The replacement 16" screen was bought off eBay but is LED backlit as opposed to CCFL as was originally fitted. We were told that this is due to the CCFL version not being produced anymore and that everything would be fine as long as we remove the inverter, but after powering on the laptop the screen was really dark, akin the lowest brightness setting pre screen replacement. We tried adjusting the brightness using the functions keys, the acer ePower management utility, the Vista power management utility and with third party screen brightness controller software but nothing so far has worked. I also tried the BIOS to see if I could adjust the brightness there (Like on my Dell) but the option isn't available. Vista recognized the display as a generic PnP display and assured me that it was working perfectly . So in an attempt to remedy this I updated to the VGA_Nvidia_v7.11.15 driver (the laptop has an Nvidia 9600M GT GPU) to see if that would resolve the brightness issue but it unfortunately didn't do a thing I'm close to the end of my tether with it and my repeated requests for the hammer from my toolbox have not helped matters either. Has anyone else had a similar problem or could offer advice on how I could get this remedied? Any help would be greatly appreciated -Paul
Got a multimeter? Check voltage across any backlight LED, should be around 1,7-2,2V range. Sounds like they aren't being powered.
Hi Anderson, thanks for your reply I'll check that in the next day or so (When she isn't using it) but I'm fairly certain that it's receiving some backlighting power, just not enough. There is some light coming from the backlight, it is just very low. Confusingly the brightness increases once the laptop is plugged in, so obviously some of the power management settings are working; just not enough of them.
Bump! Any ideas guys? I'm fresh out of ideas at this stage, save for flashing a new bios or installing a new GPU driver. I'd really appreciate some advice
Did you check the backlight LED voltages? Do you still have the original CFL backlight or did that break/get thrown out with the old screen- I'm wondering if you can swap the backlights around with a little work.. Otherwise I would say the power circuitry for the backlight/screen doesn't work too well powering just the leds, vs the inverter + CFL...
Hi Neil, thanks for your reply; sorry for taking a few days to get back to you I haven't checked the voltages going to the LEDs yet as she can't really afford to be without the laptop time wise (She's studying animation and has a production booklet due on Wednesday), but I'll check it next weekend. It should, in theory, be possible to swap the CCFL lights across as the crack in the original screen only affected the LCD panel, I was just be hesitant to do the swap as it would probably void her warranty. We removed the inverter before attaching the LED screen, but would it help if I put it back in? I'm not sure what sort of voltages the inverter works with and ramps up to, but I'm assuming that the voltage it puts out would probably fry the LEDs. I'll check for loose connections at the same as checking the voltages along with checking for any grounds which may have come loose. I'll report back when I've checked the voltages, but I'm thinking that I may be somewhat up a messy creek without a paddle
