I have a JCC Intervalometer with a problem! Bulb setting set to 2 minutes, interval 1 sec., number of shots 15. Actually, the numbers do not matter. When the unit gets through the first exposure time, the interval number changes just once and then the numbers 99:59:59 appear and the count down continues from there, but the shutter no longer responds. The unit has worked before. What am I doing wrong?
3 second 2 minute 2 second interval, and it should work. The interval has to be a bit longer than the shutter time. The shutter time has to occur in that interval. A one second interval will not do a two second shutter.
EDIT: changed interval, longer than the shutter duration. See comments. This manual posted by twalberg says "at least two seconds".
Sounds like a broken unit => RMA | Service center | Get a new one
I don't think there's something you can do about it (if you could, you wouldn't be asking here), especially considering it was working before. This is definitely not a standard behaviour.