Dead Acer Monitor

[noah95]

Hello everyone, i have an old acer monitor "AL 1916W"

it was totally dead but after i replace some bad caps now the led turns green and red when it's in sleep mode.
but the picture at all no backlight or a dim picture in the LCD.

i just wanted to know how can i test the backlight and the lcd or from where to measure the voltage going to the backlight or the lcd, to know if the problem in the psu or not.

i did test most of the component there if there's a short but they seems fine.

i'm trying to fix this monitor and some other stuff for the purpose of learning so i hope some help and advices from you guys ^^

 

[unclejed613]

on the lower left corner of the power supply board, just above the far left connector with the pink and white wires, one of the blue ceramic capacitors looks discolored, and is likely shorted. the pink and white wires go to your backlight. i've seen such a failure before. IIRC these are 30pF/500V capacitors.

 

[Nigel Goodwin]

on the lower left corner of the power supply board, just above the far left connector with the pink and white wires, one of the blue ceramic capacitors looks discolored, and is likely shorted. the pink and white wires go to your backlight. i've seen such a failure before. IIRC these are 30pF/500V capacitors.

Those types of high voltage little blue capacitors do commonly fail, although I've not seen any fail in that position. However, the discolouration in the picture isn't very clear, and it looks more like the adhesive holding the capacitors in place.

 

[unclejed613]

I've not seen any fail in that position.

i've seen several fail on those backlight outputs. and they do darken when they short. the blue dye in the outer coating is temperature sensitive (makes the laser etching of the component value show up better).