SPARK & POP!! SH*T!!

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A small but deadly sound filled the room as my apple IIe smolders. Luckily, the top lid was off and I was jacked from natures gift of caffeine, I caught a glimpse of the vicinity. From what I could remember, puff of smoke poofed from the R16 (capacitor?) area. The upper right hand corner of the logic board was icky smelling and reeked of death. But the prompt was still active, THANK GOD! Do you think changing this 1982 capacitor would even matter (i don't see any damage) or would not replacing it only cause more problems?

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speedyG's picture
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Re: SPARK & POP!! SH*T!!

Hello pc154864,
unfortunately such events will be increaseing in the next years and decades ....
take yourself some time and search google for a mixed combination of the
following terms:
electrolytic capacitor acidsplash obsolecence
the problem is the age of the used dielectric material....
it does make sense ro perform exchange of the electrolytic capacitors -
if you you that one out of the bunch starts leaking ( generally recognitable
by smeary leakage close to the PCB or bulging tops...

physics about heat and storage leading to aging of that caps is well enough explained
in the basical pages related to that topic in the internet:

http://en.wikipedia.org/wiki/Capacitor_plague
http://www.capacitorlab.com/visible-failures/

when performing change of the capacitors it is recommended to use same values or
only slightly higher values but you better avoid smaller values !

This is valid to the capacity and to the voltage limit.
1000µF might be replaced with 1200µF but values below 1000µF like 820µF should not be used
if the capacitor has voltage limit at 16V it might be replaced with 25V type but 10Volt type or also 35 Volt type should not be used.
Value notation usually like: 1500µF/16V or 100µF/10V.

BEWARE: that capacitors have polarity ! mark the former position of pluspol at PCB !
changing polarity will surely lead to exploding capacitors with acid spill....

http://www.elna.co.jp/en/capacitor/alumi/catalog/pdf/al_caution_e.pdf

Note beside:
capacitors are usually noted as "C" like C16, C25
while "R" notation indicates a Resistor , like R15, R34 etc. .....
so if it really was a device marked as R16 it rather more may be a carbon resistor that "flamed away to nirvana"
indicated by change of color or visible rest of burning... or crack...
sincerely speedyG

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Posts: 832
Re: SPARK & POP!! SH*T!!

Speedy,
When replacing old capacitors with modern ones, does one need to be certain of getting new stock? Are they longer lasting than the old ones? How much longer? Should we all be swapping out our old power supplies and motherboard caps now? Was there a transition time when the computers were built with longer lasting caps (like say the Platinum IIe's and //c+'s)?

Mutant_Pie

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Re: SPARK & POP!! SH*T!!

Hello,
After reading your post and hearing that your Apple IIe started to smell like bad coffee, I realized I'd seen this problem before.
http://forums.macrumors.com/showthread.php?t=1670186
I don't know if this is your exact problem, but it should provide some helpful instructions and tips.
Tom

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Re: SPARK & POP!! SH*T!!

fri0701 wrote:

Hello,
After reading your post and hearing that your Apple IIe started to smell like bad coffee, I realized I'd seen this problem before.
http://forums.macrumors.com/showthread.php?t=1670186
but it provides some helpful instructions and tips.
Tom

Hello mutant_pie,

hello to the other members here

- yep it´s getting closer to the time that age might start killing the one or other part within our "artifacts"....
- unless the computers are not inspected carefully periodically some users not taking care about the problem will be torn back to reality with nice demonstation shows about "what can happen if electronics fail....."

the point is that we are faceing different kinds of problems from different sources:
one problem in the 80´s, was that cheap manufacturers from taiwan spilled very bad capacitors in the market
and it took several years till the mess was discovered and published
due to the fact that the mess started quite a while after the diestribution of the bad material...
( exploding electrolytic capacitors from taiwan )
time between production of the shit ( 1981 till 1985/86 )
and the massive failing of that components ( started in general in 1986 till up to the 90´s )
and a lot of that bad caps are still ticking around within parts coming from taiwan even today
if they haven´t been stressed by daily use.....
sometimes that "bad toxic stuff" had been used for repairs...
- so you sometimes catch sight of them in parts you would have not expected them.....
in the meantime i have a solid mistrusting against any electrolytic capacitors from taiwan or china
- and i replace them imediatly "on plain sight"
with ones manufactured by US or European or well known Japanese companies.

The second point of trouble is just the simple aging of them.
But that is within normal conditions visible: residue leaking out at the bottom or small raising of the tops of them.

A very good indicator is the area and condition the parts are working:

the hotter the area gets in operational mode the faster the aging and the higher the risk of failing....

that´s anyhow a very important point: heat within electronic devices is always a indicator for bad design...
the moment electronic parts are operated in areas with temperature above 45 to 50 degrees Celsius
is the moment that aging and obsolesence starts counting down away the years in the lifetime of components....
so it´s always a good idea to keep an eye on the ventilation and air exchange within any computer - thats a general rule....

the third point is the so called security or limitation boundary.....
in general rule: every component should have e "reserve" limit of about 20% to 30%.
So for example if the powervoltage in the operationel area is limited by regulation to a value between 11,4 and 12,4 Volts the limit of the capacitor should be: 20% out of 12,4 = 2,48 Volt ( "reserve" ) so the limitation should be labeled to the next higher value resulting from original value 12,4 + reserve 2,48 = 14,88 Volt resulting to the next higher value => 16 Volt.

But remember that within circuits some engineers have calculated with wide range of voltage ( for example switching power supplies , because within such circuits also so called "spikes" might happen or occure regulary....
That´s the reason that in some prts of powersupplies parts are used with limitation up to 400 Volt or higher - nat to talk about the voltages within monitors that even exceed far beyond this limitations.

Anybody heving interest in that stuff - it´s a well known problem allready for many decades ( thinking about the
lightbulb even for nearly a century ) and there is plenty material out there related to the
term of "obsolesence" ( - and please recognize that there are different types of obsolesence.....

and back to your question mutant_pie,
nope there is no need at the moment to kickon the soldering irons for massive exchange
but there surely is an indication of keeping eyes open to the topic and keeping awareness to the problem !
If the device is used in an area with bad conditions ( hot areas ) or with "heavy load" apple II occupied with
full loaded slots several "maximum sized interface cards" and hot powersupply
- then it´s a good idea of searching for better solutions ....
(like using "heavy load" powersupplies like the one sold formerly by AE )

And there are solutions also given for the serious collector:
exchanging the regular power supply against one with heavy duty limits
( +5 Volt = 7,5 Amp or more / +12 Volt = 4 Amp or more )
and just keeping the original powersupply on the shelf ...
- in case of sale - the original powersupply may then be swapped back in the system....

speedyG

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Re: SPARK & POP!! SH*T!!

Alright so I opened the power supply from the apple //e. Of course, you guys were all right. A rectangular mustard colord regulator had blown, and I mean exploded, out the front. It reeked like sulfur and ear wax was everywhere. I did notice another regulator in there too, pre-exploded. Is that one a "back-up"?

obviously im not going to use the hardware until this problem is resulved, but where on earth would I find a replacement for this?

Should i wear protective gloves when removing it?

speedyG's picture
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Re: SPARK & POP!! SH*T!!

That smeary stuff is BOR-acid. You should at least wash carefully your hands after clening up the mess.
The one link in previous posting has fairly good description on nest steps....
Beware don´t get any of the BOR-acid in your eyes while wipping them carelessly !
There are plenty pages in internet about carefull handling with BOR acid and cleaning it away.....
and getting replacement components ? - see previous mantioned posting and google for local sources....
sincerely speedyG

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In early days I had a lot of money but no time - now I have no money but a lot of time....
the second part includes less friends but a lot more joy on life....

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Re: SPARK & POP!! SH*T!!

What about using two separate chargers? Like cell phone wall chargers. one that clips to the +5v and another to the +12v. Would that even work? maybe attaching it straight to the Logic board?

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Re: SPARK & POP!! SH*T!!

It´s probably for short testing O.K. - but for regular use it´s a bad idea:
first of all the voltages in the regular powerunit have fixed correlation to GND
- with different charger this correlation to the common GND is very instable....
this bears the risk that one of the voltages runs out of limits and may damage the
RAMchips. Second only 2 Chargers would not solve the problem. Most of the chips really work with
only +5V or +12 Volt - but the RAMchips at least if there have been used 4116 chips demand also - 5 Volt too....
and also some small amount of +12 Volt is also requested.
And the text up till now has not even treated the minimum amount of power demanded from that 4 chargers:
+ 5 Volt minimum output 1,8 Ampere
+ 12 Volt ( only if no diskdrives are connected ) minimum output 0,4 Ampere
- 5 Volt minimum 0,25 Ampere
+ 12 Volt minimum 0,1 Ampere
and also not mentioned up till now the spikes and other disturbing signals within that kind of powersupplies....

Under that circumstance it´s better idea to use an old PC-powersupply from XT
( not AT because it uses other kind of switching onm and off and powersense ! )
that solution would be quite similar to the kind of powersupply mentioned as
"Buggie Powersupply"......
similar kind of solution is mentioned with one of my webpages:
http://www.appleii-box.de/H037_AppleIIupgradingPowersupllies.htm
at least you will get some more informations about adapting other solutions....
speedyG

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In early days I had a lot of money but no time - now I have no money but a lot of time....
the second part includes less friends but a lot more joy on life....

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Re: SPARK & POP!! SH*T!!

Maybe just ordering and installing new Electromagnetic interference suppression capacitors would be my best bet.

Do you think they make newer versions of these? like you said before, I don't want the shitty ones from Taiwan.

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Re: SPARK & POP!! SH*T!!
amauget's picture
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Re: SPARK & POP!! SH*T!!

Higher voltage is okay, even better.

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