Thanks Mainecoonmaniac and donkee. Unfortunately I live in South Africa and I'm pretty sure the local Minolta distributors won't have a clue how to fix a spotmeter, although I will enquire. And shipping to the US for repair would be prohibitively expensive. So to start with I would like to have a look at it myself - I'm fortunate that I have a lab of electronic test equipment at my disposal, so I should at least be able to figure out what's wrong. Of course if I need a replacement part then this may not be available. But I'm hoping it may just be a bad solder joint or oxidised connector.