APPLE //gs IIgs INTERNAL POWER SUPPLY REPAIR KIT: DYNACOMP, .50 + .10 s/h

Description

Presented to Apple II experts
at KansasFest
, July 24, 2014.
APPLE IIGS /IIe POWER SUPPLY REPAIR KIT
FOR DYNACOMP INTERNAL POWER SUPPLY
IIgs model  # 699-0126  or for
IIe model  # 699-0133
DYNA COMP CORP. of Redwood City, CA made internal power supplies
for the Apple IIgs and IIe during the last years of Apple II production.
Dyna Comp Corp. was founded in 1987, and Apple II power
supplies were among its first commercial products. These
power supplies, made in USA, tended to fail suddenly, without
warning. Thousands have been discarded, unfortunately.  But
80% of those failures happen because of two small electrolytic
capacitors.  The IIgs power supply can be restored to life, merely by
replacing those two capacitors!  I first learned of this at KansasFest
1996, from someone else's presentation; the 1996 speaker at a IIgs
color monitor session described this specific IIgs power supply
repair.
Note that this repair is
specific for the DynaComp IIgs power
supply;
it does NOT apply
to the Astec brand IIgs power supply, made
in Hong Kong.
The solution is simple: Open the power supply, and identify the
two bad electrolytic capacitors  (1 mfd, 35 volts), then desolder
them, removing them from the motherboard. Replace the two
bad capacitors with these:  (1 mfd, 50 volts).  Viola! In most cases,
this solves the problem and the power supply is restored to life.
WHAT YOU GET FOR
.50 PLUS SHIPPING
(1)  Two electrolytic capacitors: rated at (1 mfd, 50 volts)
(2) Two spare capacitors of same type   (Total of four capacitors)
These capacitors are top quality! They are certified to function well
at temperatures up to 85 degrees centigrade
(185 degrees fahrenheit).
The power supply is unlikely to reach that high temperature level
(2) Four 4" x 6" clear color photos, close-ups to guide your
soldering
(3)  Two photocopies of my detailed instruction sheet
.50 plus .10 shipping
(Shipping is FREE if shipping combined
with any other larger purchase)
NO WARRANTY, BUT ODDS
OF SUCCESS ARE GOOD
Ordinarily, I offer a 60-day money-back warranty on items I sell.  But
for this power
supply repair kit, I cannot give a warranty, beyond
a guarantee that all my capacitors are
brand new and have not
been taken out of other equipment.  Failure could be a result
from faulty soldering. It could also be a result of failure of
other components besides
these two capacitors; after all,
the IIgs and its power supply have been around
since 1986,
making them more than 30 years old.  Still, this repair
work has an 80% chance of success, when soldering
has been done properly.  So, do it!
SHOULD THE TWO CAPACITORS BE
REPLACED IN
ADVANCE, IN A
CURRENTLY WORKING POWER SUPPLY?
No!  Wait until the power supply actually fails!
My repair philosophy
is,
"If the unit
hasn't yet failed, then don't fix it."
Due to faulty
soldering, you
could end up with a
dysfunctional unit.  But it would
be prudent to buy one or more of my repair kits
now, to set aside
until the day when they are actually needed.
Get the kits now
;
My age is now 74.4 years  (8-1946), so it is difficult to predict whether I
will be around years later,  when your DynaComp power supply
really
needs
this repair
kit.  ;-)      Be prepared, get it now.
Apple II forever!
SOLDERING TECHNIQUES:
THREE OPTIONS
NOTE that these electrolytic capacitors are polarized, each marked
on its painted
casing with a negative (-) lead.  Be sure that the new
capacitor's polarized position
on the motherboard matches that
of the old capacitor.  When viewing into
the power
supply from
above, both capacitors have their NEGATIVE  lead
closer to the
power supply
end that accepts the AC power cord and switch;
i.e., towards the
left end of the unit.
First,
you can desolder the leads of the two capacitors directly,
removing the old capacitors
from the printed circuit board. With
this approach, it can be difficult to identify
visually the correct
pins beneath the circuit board.  A mistake made here would
mean that the wrong component could be loosened and
desoldered!  A second problem
with direct desoldering is that
DynaComp Corp. used a high temperature solder, and it is
difficult to liquify that solder with an ordinary small soldering-
pencil.  This approach is most
feasible if you use a professional
soldering station, in which the tip temperature can be chosen
directly. My guess is that a tip-temperature of approximately
420 degrees Fahrenheit
would be best.  But a complication of
high-temperature desoldering is that the components
themselves are exposed to high temperature, potentially
damaging the components with high heat.
Second,
use a tiny round twist drill, spun by a Dremel precision
drill, to
bore a tiny hole at the positions of the two old leads, drilling
through the old
solder. Then the old leads are clipped off, the two new
leads are inserted through
the two drilled holes, and the new
capacitors' leads are fixed with fresh new solder.
Apply vertical
pressure slowly, to avoid separating the solder trace on the
bottom
of the motherboard. If the trace becomes separated
from the motherboard,
this can be repaired successfully by
soldering tiny insulated wires to
reconnect any traces that
were accidentally separated from one another.
Third,
the soldering technique that I now favor, as the
best, is to use a pliers or small vice-grip to crush each
of the two older capacitors, and then use the two old
wire-leads
as "stalks" on which to solder the new
capacitors. This technique guarantees that the correct
wires are used, and it allows normal low-temperature
solder to be
used, thus avoiding heat damage to components.
The downside of this
approach is that it can be tricky to
position the old lead and the lead from
the new capacitor,
close together so that they
are bonded by the fresh solder.
.50 plus .10 shipping (first class package)
Generous combined shipping discount
On hardware purchases, you pay mainly the single largest shipping cost.
Other hardware items in same parcel, will be shipped with minimal
extra cost.  Weighed shipments will be the actual cost.
Free local pickup at Gallup NM  87301.
I am a self-proclaimed Apple II expert, having authored five articles
in Apple II magazines during the 1990s
.
My Apple II inventions  were
featured at Apple II conferences  KANSASFEST 1996,  2013, 2014,
2015, 2017, and 2018  at
Rockhurst University,
Kansas City  MO.
==============================
INTERNATIONAL: SALES
TO OTHER COUNTRIES
I will ship to other countries, but special
conditions will apply:  Insurance is included when
shipped by medium or large priority mail
boxes, internationally.  Payment must be via
PayPal, in U.S. dollars.
I will retain the post
office receipt as proof of mailing.  The "
extra items
shipped combined are shipped free
" rule applies
only on shipments in flat-rate boxes;  for
weighed shipments, the shipping cost is based on
the actual combined total weight. Also, I must
guess at the weight / postage cost.
I will guess
slightly high, but I will refund any excess
amount paid for
shipping/postage,
to
the buyer's PayPal account,
after
the item has been  mailed.
=======================================
Stephen Buggie, psychology professor,  UNM-Gallup