Foldnak m2 not stitching

Hopefully somebody can advise please....got an old m2 booklet maker that seemed to go out of timing other day.adjusted arm that triggers the microswitches but also noticed that left micro switch was burnt out. This controls the clinching solenoids by sight and test. Although ive put new switches on it seemed ok for a few then timing went again and now the staples are either not entering the saddle or not bending to hold book together....could it be the black relay.....dil 04-40 and what does that do or activate....ive no manuals whatsoever for timing or electrical....thanks in advance