Hello Mike,

I've found a schematic and the meter is repaired. A few resistors in
the resistance range were damaged by battery acid and have been
replaced. It's now fully operational again.

However, a generic schematic wouldn't have been of much help here, at
least not to me; someone more experienced might get by, though.

BTW, there's quite some extra circuitry in the meter, to prevent damage
from overvoltage/current. 3 batteries (9V for the resistance, 9V for
the protection circuit and 1.5V (mono) for the lower resistance
ranges).

Anyway, thanks for the tips and help in getting this meter fixed.

Grtz,

Peter.