Kaypro Power supply

[Kurt Pieper]

I'm looking for two schematics of the power supplies:

CALIFORNIA DC 60 0205 02 REV F P.F-B

and

1983 BOSCHERT INC ASSY 45-14603-0 REV 3 or 13?

Two Kaypro's 4/84 caused problems on Tuesday.

The capacitor of the CALIFORNIA power supply is renewed. Are already desoldered. Delivery is on the way. The computer should work again after installing the new capacitor. One could generally omit the capacitor, since it was built in for interference in the radio range.

The following problem occurs with the Boschert power supply unit: Computer works for a while and suddenly switches off the house network.

FI protection circuit becomes active.

SHORT C H L U S S.

The error must be in the Boschert power supply, as this power supply causes the same error in the other Kaypro. My suspicion falls on the interference capacitor (green component).

greeting

Kurt

[Kurt Pieper]

www.mikrocontroller.net/topic/545294#new

or

www.mikrocontroller.net

Analogtechnik

Kaypro 4/84 Netzteile

[jopil]

Hello Kurt,

Take a look at this one. Is the BOSCHERT POWER SUPPLY Tech-Manual with full schematics.

http://www.bitsavers.org/pdf/boschert/Boschert_OL25_Single-Stage_Power_Supply_Maintenance_Manual_May79.pdf

John 

[Kurt Pieper]

Hello John,

Thanks for the information.
i look at it

Greetings from the Rhine

Kurt

[Kurt Pieper]

Hi guys,

nice greetings from Germany.

See this link.
https://www.abebooks.de/9780801976261/Chiltons-Guide-Kaypro-Repair-Maintenance-080197626X/plp

Does anyone have this book or a PDF file?

greeting
Kurt

[Mark T]

Hi Kurt,

You might try asking in vintage Computers forum on vintage-radio.net

https://www.vintage-radio.net/forum/forumdisplay.php?f=16

Mark

[Kurt Pieper]

Hello Mark.

Thank you for the info.

Kurt

[jopil]

Hello Kurt. Are you still looking for the "Chilton's Guide to Kaypro Repair and Maintenance"  book?

If yes, drop me a note to send you a link for downloading it.

Regards,

John

[73VW]

OMG, is there actually a thing? Would you mind sending me a link as well?

I'm just happy to be part of a conversation related to KayPros. I grew up with an 8088 KayPro PC and was a huge fan.

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[Kurt Pieper]

Hi guys,

I am surprised that there are no circuit diagrams for the Kaypro computers from 1980 from Boschert and Califonia DC.

Has anyone scanned the plans?

That's a very important factor for the preservation of retro computers.
Yes, of course, I can install a Mean Well power supply. But then my kaypro messed up. It is important to me to have an original Kaypro 4/84.

I learned to program with Kaypro and it was and still is a great time.

Now soften up and hand out the circuit diagram for the Califonia dc power supply. I have the Mod# LR5301-15 and Ser# 159443.

greeting
Kurt

[IOANNIS PILIOUNIS]

Kurt, take a look at this
https://www.electronicsurplus.com/search/CALIFORNIA+DC

John.

P.S. Did you eventually manage to source the Chilton's
Guide for KAYPRO? If you still want it I can send you
the link to download it.

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[Kurt Pieper]

Hi John,
thanks for the information.

I have the Chilton's PDF.
There is also no circuit diagram of the Colifornia dc power supply.
It's in the book. "You won't have any problems with this power supply for the rest of your life. Maybe with the on/off switch"
Humor from 1984. Grin...

Without the schematic it will be very difficult to repair the Colifornia dc power supply.

Again as a reminder. It is a power supply from 1984 for Kaypro computers.

The power supply has a short circuit on the circuit board. It clicks. Varistor prevents the 'bang'

During the test I use a PeakTech Trentrafo. The part is good for this use.

The Boschert power supply works again, since only the sturgeon capacitors were defective here.

The second Kaypro 4/84 works again.

I love the Kaypro's Here in the 80's a very good product was created in the USA.

Kurt

[Mark T]

Maybe the only way is to draw a schematic from tracing the connections on the pcb. 

If its a switch mode power supply it might help to identify the main IC and find a datasheet.

I was able to fix a switch mode power supply in a samsung TV over ten years ago like this, replaced the schottky diode that had gone short circuit and the switch mode controller IC. That TV is still running ok.

[Kurt Pieper]

Hi,
thanks for your information.
Yes, I think that's the only solution at the moment.
I'm not sure I can do this.

Here is a picture of the power supply.

I soldered the suppression capacitors.

The rectifier, 1 large electrolytic capacitor, diode one contact.
All parts OK.

It will be a big task for me. I've been an electronics hobbyist since the 70's.

I2.Picture shows the Kaypro 4/84 with Gotek LW.

greeting
Kurt

[Kurt Pieper]

Hi,
I converted the predicted Kaypro 4/84 with the Gotek LW with the MainWell RT 85B.

The California DC power supply is now my research object.

greeting
Kurt

[Kurt Pieper]

Hi,

if anyone has the wiring diagram of the califonia dc power supply then please provide info.

Here is the replacement net - not retro but it works very well.

Kurt