No Backlight--new parts

[wayout2day]

Acer Aspire Laptop... 5733Z-4851... Customer presented laptop with broken screen. Visual inspection showed cracked screen with backlighting. Laptop had been sitting for over a year. Previous repairs included replacement of keyboard due to spill.

Removed and reformatted hard drive with no issues. Reinstalled windows and updated to date with no issues. Used external monitor to complete Windows/software installation.

Ordered new replacement LCD. Removed old LCD. Visual inspection showed no further issues. Trouble began with installation of new replacement LCD. Problem with plugging in video cable. Replaced Video Cable with new cable. Visual inspection inside of laptop showed no signs of spill residue or other damage.

Dark on new replacement LCD. External video showed ok video. Light shined on new replacement LCD showed fine video image--NO BACKLIGHT. Sent LCD back to supplier. Supplier tested their LCD, no problems. Supplier sent another new replacement LCD. They tested the replacement first.

Received 2nd New replacement LCD. Installed LCD with no issues. Still NO BACKLIGHTING.

Checked Windows (Windows 10 1803)... no change when adjusting brightness -- on LCD or on external monitor.

Is this some kind of a motherboard issue. Is there a step I am missing. I have replaced many many LCD without this issue before. Any suggestions ??

 

[wayout2day]

UPDATE: tested the old broken LCD Screen and there also was NO backlight. I didn't find anything elsewhere online, so I decided to replace the Motherboard. cost about $50. ... waiting for the shipment, will update at that time. any helpful comments welcome.

 

[pendragon1]

ive seen an acer laptop with win10 1803 that automatically sets the brightness to off and the control buttons are reversed for some reason. on boot you had to press the brightness down button to increase the backlight.

 

[wayout2day]

ive seen an acer laptop with win10 1803 that automatically sets the brightness to off and the control buttons are reversed for some reason. on boot you had to press the brightness down button to increase the backlight.

I get the motherboard on Tuesday..... i will check the brightness control....that would be on the Keyboard I assume... interesting comment... this is what i am looking for... just seemed so odd... could the MB power to the backlight been shorted somehow... TY

 

[pendragon1]

I get the motherboard on Tuesday..... i will check the brightness control....that would be on the Keyboard I assume... interesting comment... this is what i am looking for... just seemed so odd... could the MB power to the backlight been shorted somehow... TY

only thing I could think of. the backlight is internal, theres no corrosion, so it should work.
edited speeling

 

[IdentityCrisis]

Sounds like it was the board, but the windows 10 issue is interesting. I'd verify windows 10 with the new board before any more hardware replacement. Does acer have any goofy power manager programs that could be the issue?

 

[Rvenger]

Blown inverter fuse on mainboard. Broken screen blew the fuse and its damn near impossible to replace those small fuses without some highend soldering equipment.

Happens all the time on the Lenovo Thinkpads and I end up replacing the mainboard and all is good.

 

[wayout2day]

OK, got the replacement Motherboard. Installed today. Backlight working fine.... works terrific..... YAY ! ...... i'm not sure if if managed to short out the MB lead while replacing... but i hear Rvenger about the Blown Inverter Fuse.... just have never had it happen before... forewarned and will act accordingly in the future.... Thanks guys for all of the advice and views of the post....