2712 SA with display (and normalization) issues #photo-notice


Ronan
 

Greetings Tekkies!

I've got a 2712 SA -- it had been sitting in storage some years (unknown time). When I plugged it in, the traces & text was shifted below the bottom of the display area. I let it run a couple hours; the trace & text eventually wandered up to and just above the top of the display area. The trace/text is sharp and bright, but the text is distorted especially near the top left and right extremes; and it varies.

Here are two images -- the normalization failure and the distorted text (which isn't always quite as bad as this example).

Distorted text: https://ibb.co/sbYzpqR
Normalization issue: https://ibb.co/ZLGTM74

I was able to get Normalization to succeed once earlier today - running complete normalization twice in succession. I then I began exploring, doing some very basic tests, after that I reset it to defaults [Util / 1 / 1] , ran the Normalization again, wherein both the Voltage and Amplitude normalization failed.

I'm reading previous posts that I should start by replacing the battery. I will pursue that and as well attempt to become familiar with the Service manual. Also I read there are some SMD-size Electrolytic I may want to check and of course power supplies.

Should any of you worked on one of these and found the same two symptoms (sometimes Normalization succeeds and other times not -- along with distorted Text and display drifting vertically after time) -- please let me know.

Thank you kindly!!

Ronan

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