Acer Aspire 5735Z laptop power problem

[andypandy]

This computer was working fine until I went to turn it on recently.It works fine on battery,but restarts or turns off when an adaptor in connected.I have tried another adaptor which makes no difference. When looking on the internet this model laptop,and many other Acer,and Toshiba laptops share a common problem. They are fitted with the notorious NEC/TOKIN 0E907 'Proadlizer' value of 900ufd 2.5 volt. This is a different name for a capacitor. It is used on the CPU core voltage circuit. My first thought was to replace this one item with 4- 330ufd 6.3 volt panasonic capacitors( working solution suggested by many repairers). I measured the AC millivolts on a true RMS meter expecting to read a high unstable value.My meter showed about 9 milliohm when the laptop is battery powered .I expected a higher reading when I connected the adaptor,and got the same results. This leads me to think this 'Proadlizer' is fine,and there is a totally different fault somewhere in the power supply circuit on the motherboard. There are no burn marks on the 0E907. Any help would be gratefully received.

[Sephir0th]

Re: Acer Aspire 5735Z laptop power problem

I believe You should exclude DC-IN Circuit first. Check your DC-IN Mosfets in Ohms Mode between D-S-G. Also check the voltages at D, S, and G of both Mosfets when Main battery is present and when Main battery is unplugged and Share the measurements.

[andypandy]

Re: Acer Aspire 5735Z laptop power problem

Thank You,I will try today as you stated.The laptop works fine on battery.One thing I didn't mention in my first post was that the battery charges as normal.The fault seems to be when the DC input supplies the laptop with or without a battery. The laptop starts up to the windows page then either continually restarts,or shut down. I thought if there is a capacitor faulty in this circuit.

[mon2]

Re: Acer Aspire 5735Z laptop power problem

How old is the battery? Have you tested with a new battery?

[andypandy]

Re: Acer Aspire 5735Z laptop power problem

I tested it with a battery which was new last year.This battery works fine in another Acer Laptop an Aspire 7315. A circuit or block diagram of the Adaptor input where the 19 volt goes,including how the battery connects,and is charged would help me.

[piernov]

Re: Acer Aspire 5735Z laptop power problem

Don't waste time. Replace NEC Tokin.

[Sametbey]

Re: Acer Aspire 5735Z laptop power problem

I join piernov friend. Even if you do not remove the nectoken, you can test it by adding 2 pieces of 330uf.

[andypandy]

Re: Acer Aspire 5735Z laptop power problem

Thank You