Mac Plus Horizontal Sweep Lines

[MacinPosh]

Hi Everyone,

I recently acquired a Mac Plus with a temperamental analog board which would only display a picture briefly whilst being tapped on the left side.

I tracked this problem to a failing flyback which I have replaced, but I now get horizontal scan lines across the display which I cannot get rid of (whilst also maintaining the video brightness) by adjusting the brightness knobs. The Mac itself is otherwise working

I've tried replacing R5 but to no avail.

Any suggestions?

Thanks 

 

[techknight]

Larry Pinas book probably has something on this. 

 

[bibilit]

There is several troubles with your screen, image is inverted and far too stretched.

Maybe two problems and not only one.