Acer AL1706AB no power

[vixenpc]

Hello, I have an al1706ab that had died the other day, no power, no lights, but the vpu on the logic board gets hot very fast. Using similar threads as a guide, I tried bypassing u406, no change. The big cap is showing 165v, cn302 connector is showing black= 0v, brown=0v, red=14.39v, orange=0v, yellow=4.94v, blue=0v and purple=0v (from top to bottom). I'm not sure where to check next, and thanks in advance for any help, its greatly appreciated.

[budm]

Re: Acer AL1706AB no power

Your power supply is putting out (you are getting the 5VDC and the 15VDC). The IC should never get too hot to touch so if that is what you are seeing then that is probably your problem.

[vixenpc]

Re: Acer AL1706AB no power

Hi, thanks for the reply, I was thinking the source would be the ps board because my brown wire is 0v where in https://www.badcaps.net/forum/showpo...01&postcount=6 RobertoIsRad's was 4.5v. I tested again last night (2am) and while testing I flipped the power button board away from the panel buttons to see it better. When I first plug in the ac, I get a very faint amber light for a few seconds, and while testing, I gathered readings for : u702- top- 4.28v, middle-3.24v, bottom-0.01v q701-left-0.71v, right-0.01v q702-left-3.27v, middle-0v, right-0.45v. Hopefully this may be an easy fix, if not I'll render it to the parts shelf, I have also 2 Dell's and my favorite Samsung to troubleshoot still.

[budm]

Re: Acer AL1706AB no power

That is because that wire is probably the signal control line from the logic board. For the backlights to come on, it needs BL-ON signal to turn on the Inverter and the Dimming control signal for the backlights level control, those signals will be present when the power switch is activated and the the Video signals from PC is present. The power supply only has two output Voltages: 5Vdc and 12~18VDC range for the inverter circuit and AUX circuits.
The power supply is also an always on, meaning it always running as long as the monitor is plugged into an AC outlets.

[vixenpc]

Re: Acer AL1706AB no power

Thanks for the quick reply, I'll search around for a replacement logic board, but probably just shelf it until someone brings one in for the parts bin.