I have a complete FRS-1000 system however the screen is showing ghosting most notably on text. Is this a common issue or one that might be fixable? Appreciate the system is probably 20 years old now but is almost as new otherwise.
The FRS1000A was sold in 91-to 95 and the B sold until 2002, making the unit 21 to 30 years old. You are correct it looks pretty nice. The parts are long gone on this one except maybe the Magnetron and other items to keep the radar going. With old electronics it is normally the capacitors that start to break down. You might go through it with a capacitor checker but otherwise it might be time move on to something more modern.
If you have any schematics that would help. The plotter is a bit slow and tedious by modern standards but the radar and sonar still are perfectly usable.
Available schematics are part of the manual. If you haven't located them, the manuals are hidden under the support page of the product at www.FurunoUSA.com. We don't have anything beyond that.