I had the same problem. I was on a shoot using a Minolta flash meter and proofing with polaroid. The Polaroid indicated one exposure and the meter said another. My gut feeling was to go with the Polaroid exposure which was correct. I called Minolta to see how much it would cost for a repair and it's the same for all Minolta Flash meter IV because they replace the logic board for these repairs. Note. It was 15 years ago.