Like ic-racer says, it might be better to cut your losses and get rid of the controller. Clearly it forms part of a "system" and may be nigh-on useless without the rest of the parts (enlarger chassis/head/psu etc).
If you don't have an enlarger already, you could get a "normal" L1200 chassis with a CLS450 or CLS500 head and timer.......much simpler to setup and run, assuming you need to print in colour.
Mike
PS there is a company in the UK that claims to be able to repair these units, though they failed to repair mine!