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View Full Version : Minolta PCW-1 Word Processo/Computer bad power supply



snuci
June 22nd, 2014, 04:39 PM
I found a unique computer recently that does not power up fully. It's a Minolta PCW-1 DOS-based computer powered by an 80186. It has two floppy drives, a built in monitor and daisy wheel printer. I saw a couple of web pages on this while surfing but have not found any in North America. Does anyone have one or has anyone heard of it?

Its actually a pretty neat looking PC/WP that was built around 1988 to be a transition machine from dedicated word processors to PCs in an office environment. The monitor is monochrome but I was able to read a lone floppy that came with it that was in pretty rough shape but I did manage to make an image of it. It has DOS 2.2 on it along with the word processing software (I think). I can't run it on a normal 8088 PC. More details of it are here at a small dedicated website: http://www.gudrun-und-hori.de/minolta_pcw-1

Anyway, my power supply is not working fully. The printer actually fires up but the PC end is dead. What looks like two pieces is actually one (you have to take it apart to remove the printer and they share the same power source). Here's a pic:

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The fuse is good and power gets to the power supply board. The black/white wire that goes across the power supply feeds the printer and that works (it might be straight pass-thru of 120v). I just don't get 5v or 12v anywhere. The fan doesn't work, the floppy cables don't have power and the main power to the motherboard doesn't have power either. I can redo the caps but I'm surprised most of it doesn't work. From the picture, is there anything obvious that I should look at (other than the caps that loo pretty good)?

There is no schematics that I am aware of or much information at all about this computer. It would be pretty cool to "rescue it" and see if work.

Any help is always appreciated.

snuci
July 21st, 2014, 06:09 AM
Well, I replaced all of the caps except for the two big ones. After doing so, I still see the same results; no 2v or 5v and the fan doesn't spin. I know it's difficult to diagnose without a power supply but could it be the two main caps or some other component that could kill the whole power supply?

Any help is appreciated.

IkeFox
December 16th, 2018, 06:57 PM
I have a PCW-3 with a working power supply that I have already disassembled once for cleaning. If you are still interested in this topic I could take some pictures of the psu for comparison.