I've not seen a partial line out on a DMD. Reflowing the solder joints would be where I would start.
You did mention - "Just got a new pin delivered" - If bought from a dealer - it would be under warranty.
Will try reflowing the joints. Is a hot air solder a good choice to work on these, hands a bit wobbly for the iron.
Didn't buy it from a dealer, old ebay strikes again - man I have to start looking these things over before I buy 
I think regular soldering iron would be much better than hot air.
I'd be concerned about thermal shock on surrounding components/glass, if using hot air.
