Re: Repair of Dead IIgs DynaComp internal power supply!

[buggie@capella.unm.edu (stephen e buggie)]

POSTSCRIPT TO REPAIR OF DYNACOMP IIGS POWER SUPPLY:

I've succeeded in repairing the fault that disables about 1/3 of the dead
IIgs internal power supplies.   Can anyone else help work out the repair
of  these other two faults:

(1) FUSE BLOWS EVERY TIME

(2) FUSE OKAY, BUT NO VOLTAGE ON ANY OUTPUT LINES

I can send two each of the circuit boards for the above failures (four
total) to anyone who wants to tinker with them to identify the faults.

My knowledge of electronics is minimal, yet, I solved the third type of
failure.

BUGG-POWER IIGS JR:  $15 EACH PLUS SHIPPING

I will still continue to make/sell Bugg-Power IIgs Jr. at $15 including
the fan.  $6 trade-in for each dead IIgs power supply you send me.  But
now users will have two choices for Bugg-Power IIgs Jr.:

(a) Transplanted IIe power supply, Astec, into the IIgs casing, with fan
    and LED indicator lamp
OR

(b) Repaired Dynacomp IIgs power supply, with fan and LED indicator lamp

Shipping: $4 on first unit, and $2 each for additional units ordered at
same time.

Users are encouraged to send me their dead IIgs internal power supplies.
Possibly I can repair them; if not, then casing and some parts can be
salvaged.

BUGG-POWER CLASSIC  (150 watts, $27 plus shipping)  is still available and
is preferred for full-loaded IIgs's or IIe's.  208 units shipped since
April 1996!

Steve Buggie
Psychology
UNM-Gallup
200 College Rd.
Gallupo NM 87301			buggie@unm.edu





stephen e buggie (buggie@capella.unm.edu) wrote:





: I've been transplanting working IIe power supplies into the IIgs internal
: casing,m  with good results.  14 have been made so far, and they are
: called "BUGG-POWER IIGS JR."

: Yesterday I succeeded in repairing a dead Dynacomp power supply.  In fact,
: I have replicated the repair in four units!

: There are three patterns of failure in the IIgs DynaComp power supply:

: (1) Fuse blows every time -- components look okay.

: (2) Fuse is okay, but no voltage on any line.  Components look okay.

: (3) Volts test okay with no load, but unit quits when attached to
: motherboard.  Heat scorch marks on power supply circuit board.

: This fix applies ONLY to #3, above.   It applies only to "early" Dynacomp
: power supplies.  When inspecting the unit inside, the early versions have
: one or fewer tall yellow thin capacitors at the bow-end (10v, 1000 ufd).
: (The later versions have the five tall yellows).

: To fix the unit, replace two tiny radial electrolytic capacitors:

: REPLACE THESE:  1 ufd, 35v

: NEW CAPACITORS:  1 ufd, 50v

: 	The new ones are slightly larger than the old.  Note the polarity:
: The "-" terminal faces the stern (back) of the power supply.

: I salvaged the 1 ufd, 50v capacitors from other units that died for other
: reasons.   But they are available from Jameco for $0.04 in quantities of
: 100.

: Steve Buggie	buggie@unm.edu		Gallup NM