IBM 5151 (MDA display) - common faults / gotchas?

George Rachor georgerachor at
Sun Nov 9 11:10:23 CST 2014

And it only takes a few seconds to disable the flyback.. permanently (yup.. done it too),

George Rachor		

georgerachor at

On Nov 9, 2014, at 8:43 AM, Chuck Guzis <cclist at> wrote:

> I'll add this to the 5151 issue.   Because the 5151 responds to *every* horizontal sync pulse, it's quite possible to toast the flyback transformer with the wrong frequency.  I know--I've done it.
> Contrast with a simple astable multivibrator which would simply lose synch .
> --Chuck

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