Thanks David (just found out who you are!),
Given what you said about bad mounting position, the board on the Prusa is fine (just mounted vertically on the frame behind the X stepper). Good points about the heat dissipation and I hadn't really thought about the ineffectiveness of stick-on heatsinks before; makes sense. Bad connection along the cable is very unlikely given that it affects a stepper which doesn't move at all (and has a short, straight cable run). They were cable tied but not even tightly let alone overly tight. The motors don't have connectors on the stepper end so I can't just change cables unfortunately.
Warranty! Why didn't I think of that? Voiding warranties has been a long standing hobby of mine but I surely can't have done anything to void this one! I'll drop an email to PrusaResearch first but I imagine I'll have to contact Ultimachine directly. Whether or not I can resist trying to fix it myself is another matter... :)
John
Given what you said about bad mounting position, the board on the Prusa is fine (just mounted vertically on the frame behind the X stepper). Good points about the heat dissipation and I hadn't really thought about the ineffectiveness of stick-on heatsinks before; makes sense. Bad connection along the cable is very unlikely given that it affects a stepper which doesn't move at all (and has a short, straight cable run). They were cable tied but not even tightly let alone overly tight. The motors don't have connectors on the stepper end so I can't just change cables unfortunately.
Warranty! Why didn't I think of that? Voiding warranties has been a long standing hobby of mine but I surely can't have done anything to void this one! I'll drop an email to PrusaResearch first but I imagine I'll have to contact Ultimachine directly. Whether or not I can resist trying to fix it myself is another matter... :)
John