Shorted Motherboard? - Acer Aspire One

[gnawhalak]

Hello.

I have an acer aspire one netbook..

SYMPTOMS:

No power, no charging light, fans not turning. dead.


WHAT I DID.

1. Tested power adaptor. measured 19V on it.
2. Open laptop, removed everything and isolated main motherboard
3. measured voltage directly from the motherboard across the pins connected directly to the dc jack, since this one still has a four wire cable connecting the dc jack to the mobo -- No VOLTAGE
4. removed the power cable connector from the motherboard (to test if the wire is open) continuity test is ok.
5. measure voltage across the terminals of the power cable connector un attached to the mobo but connected to the adaptor -- voltage OK



now i'm a bit baffled.. is the mobo dead and shorted? . anything i could do?

thanks..!

 

[RegEdit]

These are the kinds of stories that make me want to opt out of repairing laptop motherboards. About the only thing left to do is test the CMOS battery. How is the soldered jack connection?

 

[Martyn]

Hello.

I have an acer aspire one netbook..

SYMPTOMS:

No power, no charging light, fans not turning. dead.


WHAT I DID.

1. Tested power adaptor. measured 19V on it.
2. Open laptop, removed everything and isolated main motherboard
3. measured voltage directly from the motherboard across the pins connected directly to the dc jack, since this one still has a four wire cable connecting the dc jack to the mobo -- No VOLTAGE
4. removed the power cable connector from the motherboard (to test if the wire is open) continuity test is ok.
5. measure voltage across the terminals of the power cable connector un attached to the mobo but connected to the adaptor -- voltage OK



now i'm a bit baffled.. is the mobo dead and shorted? . anything i could do?

thanks..!

Have you tried another power supply? It could be collapsing under load.

 

[PC-Technix]

These are the kinds of stories that make me want to opt out of repairing laptop motherboards. About the only thing left to do is test the CMOS battery. How is the soldered jack connection?

Aspire one's seem to inherit bad solders on the jack connection. I think id look at the solders also.

 

[markcuk11]

Have you tried another power supply? It could be collapsing under load.

I would do this first

 

[OldSchoolPC]

I would do this first

Yeah, I worked on an Acer Aspire One the other day, albeit for virus removal (Antivirus XP 2012 and Zero.Access). I was surprised at the amount of juice that such a small laptop pulls, and how small the power supply was.

 

[mason]

bake it? do you have the hardware to be able to "bake it"

some shops have baking ovens - read up on youtube. Could be a few dry joints. Motherboards are not mad aswell as you used to be and when they get very hot they may need baking because the solder cracks on joints.

Or try a different dc jack first ( i think most acer 1's are on the fly cable?)

if its on a fly cable take that out the case and plug the psu in to the dc jack and test the other end of the fly cable see if you get 19v

 

[gnawhalak]

oh well.. too bad,... customer is on a hurry and decided to take her netbook after referring to her the present problem.. so i can't do some further testing here.. but, i'll answer some posts so this thread might be helpful for others in the future..

About the only thing left to do is test the CMOS battery.

i was not able to reset and test the cmos since it was soldered to the board..

Have you tried another power supply? It could be collapsing under load.

i did try another supply, same results though.

if its on a fly cable take that out the case and plug the psu in to the dc jack and test the other end of the fly cable see if you get 19v

yup, it's on a fly cable. did that, removed connection from the board and tested the end.. got the 19 V..

bake it? do you have the hardware to be able to "bake it"

sorry.. no ovens for baking..






i think this one hit the problem.

How is the soldered jack connection?

.. after looking closely.. since the dc jack has four pins,.. looking at the soldered connector at the board.. one end was chipped away and was possibly causing an intermittent short between the positive and negative pins..

intermittent since there are times when i check from the dc jack / soldered jack it is shorted, yet after sometime.. the short would be gone.. then if i try to plug the supply again and remove it ... the short will come back again..

i figured, it might be a

a.) bad component like a capacitor which when charged causes the short circuit
b.) the bad soldered joint which was chipped off could have caused a short inside the interconnection of the motherboard..

since the components are all surface mounted already, and very small being a netbook.. i had a hard time when i attempted to resolder the joint and looked for the cause of the short..

would be open for other thoughts on this..

 

[frenchscottie]

oh well.. too bad,... customer is on a hurry and decided to take her netbook after referring to her the present problem..

Wonder why the customer took it back just because she was in a hurry, as it wasn't working anyway. Do you think she's going to get a second opinion somewhere else?