Minolta Di520 copier problems - power supply PU1

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
 Click to see the full signature
Reply to
John Robertson
Loading thread data ...

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

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

formatting link

Reply to
N_Cook

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
 Click to see the full signature
Reply to
John Robertson

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.