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Old 5th Dec 2019, 3:14 am   #38
Terry_VK5TM
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Join Date: Oct 2010
Location: Tintinara, South Australia, Australia
Posts: 2,324
Default Re: Sun Microcomputer II Motortester 1215

Quote:
Originally Posted by Zelandeth View Post
Doesn't really surprise me that Sun kept careful guard on the service data.
I started servicing these sorts of things from the MEA1500 on for a while (OK when new but a nightmare once they got a bit older or they sent you the wrong version replacement board) and do actually have all the schematics for one variation of it, so the data was available if you had the right contacts.

The most common problems I found was (as you have found) IC sockets (loss of tension), connectors (same) and dry joints.

Both monitors were renowned for doing in the vertical output transistors once a particular cap went faulty and the HV modules seemed to go through a bad patch at one stage too.

Chopped, severed, mutilated cords/probes was next on the list which often led to component faults on the boards.

High energy ignition systems also used to play havoc with unmodified machines as well.

One other thing to watch out for is if it has metal bodied cooling fans rather than plastic ones, they break down (electrically) to the frame and randomly blow fuses/breakers/rcd's.

All I can say is, glad I don't touch them anymore (apart from a friends SUN 500).
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