That is a bummer.
Did you check the battery on it? Sometimes when light meters have a battery with an incorrect voltage they act funny. Especially the ones that took mercury batteries before they were banned. (not sure what the FTN takes)
Maybe use an external light meter?
Also, If you have an iphone you can download the light meter app. It's free and surprisingly accurate in most common lighting situations.
Yeah, I'll have to use my external lightmeter for now but I think I'll just get another body like an FM2 or something as I find the F2 (it's an F2, not an Ftn) with it's meter prism a bit too bulky.
What are the 55mm f1.2 Ai lenses go for anyways? I'm not gpmma be selling mine as I got it as a gift but it would be interesting to know how big a gift it was 🙂