Quote Originally Posted by Petra View Post
Meh, it may be the original DDC-3.1/3.2 PCB but someone might find it useful...



Most of the catastrophic failures that I saw in the DDC-2 and DDC-3.2 involved toasted FETs. Thinking on it briefly, if a cap fails it's going to either short or go open circuit (the latter being more common, as I recall)... the result of which would depend on what the cap was doing in the circuit (in a motor like this, I suppose it could be anything from borking the time constant to maybe leading to an overcurrent situation if they're somehow using the cap to throttle current through the FET... a complete circuit diagram of the pump's PCB would take the mystery out of it).

Looking at what I found Alex and your feedback from those who sent in dead pumps to ya (I was one of them .... damn, I wish I could still be giving my money to you, than to some of these other online stores) and I would tend to agree with the FETs as a main culprit as well. Basically, if I remember correctly, Laing said that the MCP 355 and MCP 3.25 where going to be redesigned circuit boards .... uh, yeah....they are redesigned all right ..... for the worse. It has been a while since took all the circuit classes as an undergrad, but this PCB is not a good design for 1.5 Amps.