Minolta Di520 copier problems - power supply PU1

[John Robertson]

I am trying to fix a 1999 copier that was running when I picked it up,
but shortly afterwards came up with two different error messages - the
first was C-11EE (PWB-B) and now it shows C-0020 which (according to the
service manual) means a problem with motor M21. Checking motor M21 shows
a lack of 24VDC, and tracing back to the master switching power supplies
I find one section that is missing the required 24VDC, but it does have
the correct input voltage.

Unfortunately I do not have schematics for the switching supply (PU1)
and so am down to eyeballing the sucker and making a stab at finding the
problem. First suspect (of course) are the capacitors and we will be
using Bob Parkers' great ESR meter on those, however I am trying to find
as much info on the machine as I can so if anyone has the schematics for
the switching supply I would appreciate a copy.

Now the machine also has another problem - caused by me (sigh) - where I
accidentally damaged the Timekeeper RAM IC (trying to back it up with
the wrong programmer because I assumed that the 11EE error meant the
Timekeeper battery was failing (almost ten years old!)) and now the
machine only shows Japanese as I blew away the English text. If anyone
can read the Timekeeper IC (SGS: M48T35Y-70PC), it is apparently the
same as a Dallas DS1644, I would also appreciate that!

Lastly I need a replacement spring hinge lid for the duplexer/scanner
lid as the bushing has blown out...

I am located in Vancouver, BC, Canada.

Thanks!

John :-#)#
PS - I do have a PDF copy of the manuals for the Di520/620 that I can
share - I just wish they had the PU1 schematics!

--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

 

[N_Cook]

I am trying to fix a 1999 copier that was running when I picked it up,
but shortly afterwards came up with two different error messages - the
first was C-11EE (PWB-B) and now it shows C-0020 which (according to the
service manual) means a problem with motor M21. Checking motor M21 shows
a lack of 24VDC, and tracing back to the master switching power supplies
I find one section that is missing the required 24VDC, but it does have
the correct input voltage.

Unfortunately I do not have schematics for the switching supply (PU1)
and so am down to eyeballing the sucker and making a stab at finding the
problem. First suspect (of course) are the capacitors and we will be
using Bob Parkers' great ESR meter on those, however I am trying to find
as much info on the machine as I can so if anyone has the schematics for
the switching supply I would appreciate a copy.

Now the machine also has another problem - caused by me (sigh) - where I
accidentally damaged the Timekeeper RAM IC (trying to back it up with
the wrong programmer because I assumed that the 11EE error meant the
Timekeeper battery was failing (almost ten years old!)) and now the
machine only shows Japanese as I blew away the English text. If anyone
can read the Timekeeper IC (SGS: M48T35Y-70PC), it is apparently the
same as a Dallas DS1644, I would also appreciate that!

Lastly I need a replacement spring hinge lid for the duplexer/scanner
lid as the bushing has blown out...

I am located in Vancouver, BC, Canada.

Thanks!

John :-#)#
PS - I do have a PDF copy of the manuals for the Di520/620 that I can
share - I just wish they had the PU1 schematics!

--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

I would look for a connector problem or wiring break in the moving, copier
electronics is very reliable. Otherwise too much of a coincidence.
Some control signal that is disabling part of the ps perhaps?
one of those flimsey paper path microswitches or lens/mirror assembly
traverse limit switches getting mispositioned/dislodged could be another
such a cause

 

[John Robertson]

I would look for a connector problem or wiring break in the moving, copier
electronics is very reliable. Otherwise too much of a coincidence.
Some control signal that is disabling part of the ps perhaps?
one of those flimsey paper path microswitches or lens/mirror assembly
traverse limit switches getting mispositioned/dislodged could be another
such a cause

Yes, those were indeed my first suspects, however as far as I can tell I
have eliminated them by re-seating all connectors, after examining their
pins for wear, and the problem does appear to be electrical.

Thanks,

John :-#)#

--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."