Recently I stumbled across a IBM 5150. With it came a Magnavox Professional PC Monitor 80 (monochrome). The display is super sharp and great...except for the horizontal line going through the middle that looks like the paint on a road (dashed horizontal line). The PC itself I think works perfectly. I am able to execute basic scripts, boot msdos 3 off either floppy drive (it has a hdd but I think that might be dead as it doesn't spin up). Because of this, I'm assuming this is an issue with the monitor instead of the computer.
The line itself only appears after the initial blinking cursor and the IBM/DOS logos appear and it always looks exactly the same. I have opened the back of it and looked at the caps and fuses and both at least visibly look fine. A strange thing I noticed is if I touch the "v. lin" dial (see 2nd pic right most) the text on screen very lightly vibrates.
Anyways, I'm wondering why this horizontal line is appearing and if there is any hope to saving it?
https://postimg.cc/yJmY4SMR
https://postimg.cc/FfWCKPXX
The line itself only appears after the initial blinking cursor and the IBM/DOS logos appear and it always looks exactly the same. I have opened the back of it and looked at the caps and fuses and both at least visibly look fine. A strange thing I noticed is if I touch the "v. lin" dial (see 2nd pic right most) the text on screen very lightly vibrates.
Anyways, I'm wondering why this horizontal line is appearing and if there is any hope to saving it?
https://postimg.cc/yJmY4SMR
https://postimg.cc/FfWCKPXX