# Acer Aspire 3680 No Power, no lights - Power Supply Blinking



## etbrown4 (Apr 24, 2012)

I expect that the most common answer for this problem ,may be a defective power jack. There may be other answers as well which I'd like to hear about.

This laptop mysteriously died overnight one night, while not in use. There had never been any prior problem. It was working perfectly with no symptoms like an intermittent charging light etc. I tried to power it up the next day, and nothing!

With the power and battery off, I've held down the power switch for over a minute and then attached the power, but no difference.

I've studied the jack closely and it does not seem loose, nor does the center pin seem loose.

Before trying a new power jack, is there a way to trouble shoot the jack to see if power is coming through? I have 19v dc at the power connector on the power cord, before connecting.

After some dis-assembly, I see terminals pc1 and pc2 on the back of the board where the jack attaches. I also see pL1 and pL2.

Anyone know every tried to read voltage between any of those contacts? I tried to read between pc1 and pc2 and got no voltage. Have no idea if that is a good place to try to read voltage.

Any tips appreciated!:banghead:

P.S. I have a steady power light on the power supply before connecting to laptop. It blinks when connected, however there are no lights on the laptop at all. CMOS battery shows 3.06v.


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## etbrown4 (Apr 24, 2012)

A second psu does the same thing.


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## makinu1der2 (Jan 1, 2008)

If the AC Adapter LED starts flashing or goes out when connected to the laptop it usually indicates a faulty capacitor/fuse on the motherboard.

Check the power board connections to make sure securely connected.

Looking over the block diagram for your motherboard cannot determine test points for the power board though.

I would suggest trying another power board first.


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## etbrown4 (Apr 24, 2012)

I know the location of 3 suspect capacitors. There may be others.

Any chance you could tell me or post a pic of the location of a fuse for this board?

Tips appreciated.

PS. I've been told that if the power supply is blinking it is likely seeing a short on the mb. Does that sound right?

I'm almost positive the psu is cutting power to the mb when it is blinking. If not, and if it is encountering a short, then it would overheat or cause a fire, if it did not cut the power. 

I have to unplug the psu in order to reset it, so it will glow steady again, before connecting to the laptop..


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## b0gard (Aug 30, 2012)

one off P-channel 30-v Mosfet is shorted near the battery charger

AF4825PS datasheet | Pinouts | Circuits | Schematic for P-channel 30-v Mosfet


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