CBM8032 - wobbly screen

From: Bill Dawson <whdawson_at_mlynk.com>
Date: Thu Sep 27 20:17:05 2001

-> Since I left the big cap in place, it can only be the transformer
-> which is causing the wobble - can't it?
-> I genuinely don't know. That's the only part I've swapped in the
-> new 8032.
-> Could a flakey transformer be making the screen wobble? How do
-> transformers go flakey anyway, if indeed they *can* co flakey?

Well, actually I think the transformer is the cause of the problem, but not
in the way you are thinking. You may have an problem with the magnetic
field of the transformer being coupled to the monitor, either via the yoke
or directly to the CRT. Does the problem lessen as the distance between the
transformer and the monitor is increased?

See the photos of the Commodore Educator 64, Model 4064 at
http://www.swtpc.com/commodor.htm . I remember the general position of the
power transformer is similar to the Pets. Note the shielding of the
transformer in the photos. This was used to prevent the problem which you
are describing, and if this shielding is removed the wobble will occur. Try
placing a shaded pole motor or large transformer anywhere near the sides or
back of a modern monitor and you'll see the same wobbling effect.

Hope this helps.

Received on Thu Sep 27 2001 - 20:17:05 BST

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