Acer 7730ZG power problem

[rtstorm]

Hi, i got this notebook and it has blown charger. The DC jack was burned and work only by battery. It wont charge and i have 28ohm between + and -.

Please advise what to check. On pin 19 of PU11 i have no shorting.

I do not understand where go "VA" on page 33.

[meritosari]

Re: Acer 7730ZG power problem

i think "va" is voltage adapter, so its 19v. after system protection and stabilizing was ok, become vin as voltage input to dc/dc regulator.

cmiiw

[rtstorm]

Re: Acer 7730ZG power problem

thank you for that, i think DC/DC (PU13) is ok beacuse laptop work on battery. What i need to check here? I have 28ohm to gnd measuring on DC jack.

[Agent24]

Re: Acer 7730ZG power problem

Did you replace the jack? If it the jack burned it may have been bad, or a short could have pulled too much current through it - and if that were the case, something on the board should at least look overheated.

Got photos of the power section and jack?

[rtstorm]

Re: Acer 7730ZG power problem

Yes jack was burned and i replace it. I visualy check all component and i do not se burning damage.

[Agent24]

Re: Acer 7730ZG power problem

Do you have fuse PF7? Is it blown?

[rtstorm]

Re: Acer 7730ZG power problem

Fuse is ok, i check it

[rtstorm]

Re: Acer 7730ZG power problem

i tnink i isolated the problem, but cannot find the failed component.

[rtstorm]

Re: Acer 7730ZG power problem

i noticed that continuity test have loop, every 2 sec it stop for 0.5 sec and then continue. This happen when measuring that 38 ohm from picture above.

[rtstorm]

Re: Acer 7730ZG power problem

uhh i think i found problem. When the plus pin from DC jack burned it connected the layer inside the board. I try to poke it with wooden stick and it changed resistance to 150kOhm.

here is the pic.

how can i fix this??

[dj_ricoh]

Re: Acer 7730ZG power problem

yeee!

how many times i did that. on many models!

jump the wire straight to the fuse! melt some case plastic or some silicon to hold it!

[rtstorm]

Re: Acer 7730ZG power problem

Ok but the shorting is in the hole on the board. How to fix that

[dj_ricoh]

Re: Acer 7730ZG power problem

solder wick!

and you need a soldering iron so it can fit inside.
and try to put it in the whole with the iron!

[rtstorm]

Re: Acer 7730ZG power problem

Hmm ok i will try tomorow

[Agent24]

Re: Acer 7730ZG power problem

This is why photos should come first - it would be obvious from the damage to that hole, that it's the first thing to check

Maybe you can clear the hole with a drill? Not usually advisable, but in this case it might be a good idea. Then scrape some soldermask away and solder your wire to the trace, through the hole.

[rtstorm]

Re: Acer 7730ZG power problem

hello, i chean the burned hole and laptop worked for one day and now again burned in that area. Can i bring 19V from DC jack to battery terminal and with that isolate the DC jack part of board??

[dellxps15]

Re: Acer 7730ZG power problem

my advice is: fixing layer burn is very very hard and when it burn, the smell is terrible.

i tried to fix a board acer with that problem with a dremel and metallic tip. passed it perfectly alligned and straight and orizontal to the hole to try to make each layer isolate. after that a good amount of solder mask can keep the problem away.

that board was almost all killed ans some component in the back was damaged and for a old pentium m740 a good repair worth its value, plus lcd connector on mainboard got burned too.

http://i62.tinypic.com/sdhd1v.jpg

[rtstorm]

Re: Acer 7730ZG power problem

Is there any way to bypass the burned area?? So i can connect 19v direct to some component

[rievax_60]

Re: Acer 7730ZG power problem

Is there any way to bypass the burned area?? So i can connect 19v direct to some component

Yes, you can connect the DC in to anywhere on the left side of the fuse shown in post 8. The wire doesn't have to be thick if it's kept very short. Wire from an IDC HDD cable easily handles 5A.