Re: Can dust inside an Apple IIgs catch fire?

[Michael J. Mahon <mjmahon@aol.com>]

skylarking <petsoundsnz@gmail.com> wrote:
> On Friday, February 1, 2013 8:04:03 PM UTC+13, Michael J. Mahon wrote:
>> osgeld <kevin@hackaday.com> wrote:
>> 
>>> its easy and you wont need to know what it actually does to replace it if
>> 
>>> that is what is going on (though from your description I would agree)
>> 
>>> 
>> 
>>> In a nutshell you need a equivalent replacement part (stats are on the
>> 
>>> side of the part) a soldering iron, and maybe a half day to tear things
>> 
>>> down, do a quality job and put it back together
>> 
>>> 
>> 
>>> if it is the input cap, heres what it does... you have AC power coming
>> 
>>> from your wall that sort of looks like
>> 
>>> 
>> 
>>> mmmmmmmmmm
>> 
>>> 
>> 
>>> it gets rectified to DC though a series of diodes to look like
>> 
>>> ~~~~~~~~~~
>> 
>>> 
>> 
>>> the cap smooths out those lumps so it looks like
>> 
>>> __________
>> 
>>> 
>> 
>>> 
>> 
>>> will it continue to work, eh maybe, it might cause weird glitches, it
>> 
>>> might cause other components to fail, it might just puke out and kill your system
>> 
>>> 
>> 
>>> a appropriate capacitor by the time you have it mailed is only a few
>> 
>>> bucks, a basic soldering iron is around 10, some solder may be 3-5 bucks more
>> 
>>> 
>> 
>>> so for some time, little effort and maybe 20 bucks you can fix a machine
>> 
>>> that would cost much more to replace
>> 
>>> 
>> 
>>> course to assure thats what needs to be done requires you to crack open
>> 
>>> the power supply. Before doing that I would unplug it, hit the power
>> 
>>> switch a few times and let it sit a few days, those high side caps can
>> 
>>> and will give you a jolt.
>> 
>> 
>> 
>> From the description of the problem, it could easily be the line noise
>> 
>> capacitor. It's connected directly across the AC line inside the power
>> 
>> supply box. 
>> 
>> 
>> 
>> The definitive diagnosis is that when it goes, there is a really strong
>> 
>> odor. 
>> 
>> 
> There was definitely a strong smell that lingered for quite a while, so
> that could very well be it.

The power supply will work fine without it, though it will be a bit more
susceptible to line noise, and, conversely, it will put a bit more noise
back on the line. 

The capacitor is a rectangular prism about an inch high in a plastic case.
They are easily replaced by soldering, and can be obtained from any
electronic parts supplier (except, possibly, Radio Shack). 

-michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon