Need help with screen problem of mac plus

I think you might get more help if you posted this in the Collectibles forum. [Mod Note: Moved]

Having said that, please don't clean anything out with water. Also, from what little you described I would not think it had anything to do with a hard drive.

Leaking capacitors are a big problem with any Mac of that vintage. Washing the hard drive doesn't make any sense - perhaps they meant the motherboard? It still sounds crazy, but people do it with varying levels of success.

Regardless there's no easy fix for this. If you're attached to this particular Mac there are methods, but simply getting another one is usually a less time consuming option.

Sounds to me like a dry/cracked solder joint on the deflection yoke connector. Sadly when this happens, it can overheat the plastic plug and cause a "hot join" between the cable connector and the connector soldered to the analog board. The yoke connector is the four pin white connector pictured here at the top edge of the board.

On early revisions the pins didn't protrude very far on the solder side and caused a lot of heat dissipation which eventually cracks the solder.

If you know somebody with good soldering skills and have the correct "long reach" torx screw driver (to access two of the four screws under the top handle) then it's worth taking a look.

Try hitting the box at the left side near the top to see if the width of the picture jumps around. If it does, a dry/cracked solder joint is most likely it.

If it doesn't, and it's a thin vertical line (about 1-2mm) then the problem is a little worse.