This one had me scratching my head today. I have a Carrier chiller M# 30GB0900-550 circa 1989. I get to the unit and disconnect is off maintenance got worried so they threw it. Power it up and the unit is stuck in Initialization mode, just keeps flashing a 20 code. Check the alarms and get a 88 (not listed in the fault list on the unit). I start checking power not getting anything out to the motor protectors for start-up, although the boards have the right voltage. Flow switch closed, checked each of the thermistors nothing open or shorted. I don’t have any service info on this to know what the board looks at and the initialization steps before start-up but it’s coming in red tomorrow. I was just wondering if anyone has experience with this model or ran into this problem before and what they found. Or if something else could be locking it out and I’m missing it. I’m figuring that something in the board logic took a crap, but I just want to make sure. Any suggestions would help!