Vertical line problem is one of the most common, and easily fixed, problems. I have detailed instructions and photos in a file that I sent to the UberMod of the 68kmla, but I have no idea how one accesses it here. Let me know if you'd like it, and I can email it to you (it's only a couple of megs).

The first step just involves a simple resoldering of a few connections. Once you've done that, it may work right off the bat. If not, there's a capacitor that often goes south. Between the cap replacement and the resoldering operation, you can get that Plus back up and running for sure!