Commodore 1084 monitor showing flyback / retrace lines.

Why change the vertical output device? It's obviously working fine.

Second that on the capacitors, there will probably be one or two bad electrolytics near the vertical output section.

Continual service? Of a Commodore monitor?

I've never heard of preventative replacement of semiconductors, capacitors sure, lytics dry out, but semis don't automatically fail. By that logic, one may as well replace the flyback, HOT, power supply chopper, heck the whole monitor. If it ain't broke, don't "fix" it.

Thanks for your feedback guys. However it's been so long since I've poked around inside a monitor / TV that I am uncertain where to look.

Is the vertical section you refer to, the LOPT etc ?

I was considering looking on ebay for another one of these but if I could resurrect this one, I would save a few pennies. However it is possible, this unit may be on its way out. The brightness is up full, to get a normal picture. When using separate chroma and luma inputs from the C64 computer, colours still "interfere" with each other eg brown text on a blue background is almost unreadable.

Anyhow, the immediate problem is these lines on the top third of the screen.

I appreciate your help.

The 1084 was a good CGA monitor for the C=128, but for the C=64 any NTSC analog video monitor will do (using composite video combining luminance and chrominance information). Also, turning up the brightness / contrast of your monitor may increase the visibility of retrace lines near the top of the screen. Do the lines disappear when you turn the brightness down? If you have to turn it up to max brightness to view the monitor, your CRT could be failing. The cost of replacing the CRT could be more than that of a used PC. On the other hand, most cheap analog color TV's will have RCA-type sockets that will fit the composite video / audio cable provided with the C=64. The yellow connector is the composite output of your Commodore computer.

If it were a CRT problem the retrace lines would fill the screen. When it's just a few lines at the top, the problem is a capacitor at least 99% of the time.

target the caps that are around any hot spots like near a hot resistor the vert chip itself thay tend to dry out.