Laptop screen brightness issue

If you go into the bios on the faulty motherboard / laptop is there any options with regards to the screen or screen brightness in the bios itself. I know no the Dells you can adjust and set the screen brightness depending whether it is on mains or only battery and I normally tend to set both to the max setting, save, restart and check again ?

Also reset bios to factory defaults or optimal settings ( whatever the option is called ) and save and restart to see if that helps at all. Also the mains cable you are using , if you try a different one to see if that makes any difference ?

I've seen it in the past where we had a few models of Lenovos and picked the wrong power supply and the watt rating of said power supply wasn't enough for the laptop we connected it to, when it was connected the screen would go very dim like that and when we disconnected it ie running on the battery the screen would go back to normal. Then swapped the power supply to the correct one and it worked fine and the screen didn't go dim

Not sure if it will apply to your make / model of laptop but sometimes on the Lenovos if there is no power in the battery and it has not been charged or connected to mains for a day or more then you can't power the laptop on correctly ie you see the LED's for num lock, caps lock, accessing the hard drive but there is no display. Probably won't help but Just curious

If you disconnect all power sources ie battery and mains lead and then if the laptop is easy enough to get apart and put back together ( assuming it does not invalidate your warranty ) you could disconnect the cmos battery for 30 seconds or so, reconnect the cmos battery, put it back together and re connect battery and mains lead and power back on ??

Long shot

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Originally Posted by Phildw

Hey Dom, here's a pic of the screen with my monitor hooked up to show what it should be showing . Sorry about the reflections...

Attachment 15402

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Strange - that definitely looks like a dodgy inverter... not sure what else could cause it! Sorry...

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Originally Posted by mac_shinobi

If you go into the bios on the faulty motherboard / laptop is there any options with regards to the screen or screen brightness in the bios itself. I know no the Dells you can adjust and set the screen brightness depending whether it is on mains or only battery and I normally tend to set both to the max setting, save, restart and check again ?

Also reset bios to factory defaults or optimal settings ( whatever the option is called ) and save and restart to see if that helps at all. Also the mains cable you are using , if you try a different one to see if that makes any difference ?

Just wondering if you shutdown the laptop, remove the battery and power it only via mains or visa versa only via battery and not mains does that make any difference ?

Also thinking if you power the laptop completely off and swap the ram from a working laptop to the faulty laptop, if it is still the same then I am guessing motherboard issue or power issue as mentioned above.

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There are no available settings in the bios. Have tried default settings. The mains cable works fine on the other identical laptop I have, and have tried with/without battery/power cable. Will try the RAM swap at some point today if I have time or tomorrow.

Have you tried the screen ? If it's not the inverter or cable is it possible the CCFL has been broken in the screen.

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Originally Posted by difinity

Have you tried the screen ? If it's not the inverter or cable is it possible the CCFL has been broken in the screen.

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The OP States he tried another screen in the opening post.

Rob

I would say motherboard fault then - the ram was only for patchy colours or issues with it not displaying correctly, not with regards to the brightness. If there is not enough power provided before it gets to the inverter or the inverter is not stepping the power up enough or not working correctly then you get brightness issues, but you have already tried swapping that, the screen etc etc and it is still the same so presume it is a fault on the motherboard with ref to power or something to that effect

Ok, cheers for all your help guys :)