Re: AC adapter hissing

From: Gerry Cohn (gcohn_at_NOoptusnet.SPAMcom.au)
Date: 06/24/04 

Date: Thu, 24 Jun 2004 23:46:19 +1000

"carpenoctem" <carpenoctem@bigfoot.com> wrote in message
news:ab7fbc64.0406231429.36dea98d@posting.google.com...
> Hey all,
>
> The plug on my old ac adapter broke a month or so ago. I have an acer
> c110. I went to fry's but they didn't have a suitable replacement. I
> bought a multiplug/multivoltage power adapter and spliced the
> connector to my old adapter (the connector was the broken part on teh
> old one). This worked but the size wasn't correct so the plug would fall
> out of the laptop any time you moved it (or the wind blew). I ran w/
> this for about 2 weeks.
>
> That is the background. Recently, I ebayed a replacement adapter. I
> plugged it in and it worked fine. Except... shortly after you plug it
> in a slight hissing/squeaking becomes audible. It seems to get louder
> and louder until I, out of fear for the delicate internals, diconnect
> it. The sound is almost certainly electricity arcing, it is very
> reminicent of that experiment from science class where you can see
> elec. arc up the two poles.
>
> My questions are these:
> 1. Is this going to hurt the laptop?
> 2. Even if it doesn't hurt it, it is going to drive me insane. How
> can I stop it. I was thinking of maybe some sort of conductive goo?
> 3. Is the problem most likely in the plug or the adapter itself. ie.
> Can I splice the new head onto the old adapter?
>
>
> Thanx for your time.
> ej

Hi,
I have had to service several Acer machines because they use a really crappy
PCB mounted
connector for the power inlet. I have found that the soldering of this
connector to the board is
often very poor. In three of the last four Acers that I have looked at I
found dry solder joints on
this connector. Every one of these machines had the same 'hissing' sound
that yoy refer to.
The problem appears to be tarnished pins on the connector not soldering
properly
when the boards go over the wave. It looks like Acer have used batch of
ancient surplus stock
that they have aquired at some stage.
The problem takes a while to show up, but show up it will, as you have now
found.
After working on these machines for a while, I have permanently sworn off
Acer.
The build quality is questionable to say the least.

Your best bet, if you are confortable doing so, is to open up the machine
and extract the main board.
You will find a plastic guard *** in the top right corner of the machine
under the area where the power
inlet connector is located. This *** is attached with double adhesive and
will have to be gently peeled
back in order to re-solder the connector, Make sure you use solder with a
very active flux to overcone the
tarnish on the pins. After soldering, gently rock the connector from side to
side. If it is properly soldered it should
not move. If the solder joint is dry you will notice the terminal on the
side of the connector moving in the PCB.

HTH
Gerry

** The ultimate oxymoron - An Honest Politician! **