Ok, so I finally build and add on the DC driver board. As you can see, I did some part substitutions. It's ugly but it w seems to work. Unfortunately, on the 3rd print, the plastic feedstock had a problem being pulled into the extruder. I guess that's what I get for leaving my bot alone for a few minutes! By the time I got to the printer to untangle it, not only was there no plastic being printed but I also noticed a faint electrical smell too. Never good! The new extruder board's heavier H-Bridge chip was really hot! So, I'm thinking if I'm lucky, maybe the chip simply went into thermal shutdown. If so, maybe a heat sink is all I would need! Fortunately, when I built the board, I used a socket and I have an extra chip if I need it.So, let's see what damage was done. Let everything cool. Untangle the plastic, disengage the pinch wheel so the motor is free to move, then do some testing. I reset everything. I figure, maybe the driver chip fried. So, I use a volt meter to check the DC output using the software control panel. 6V at half speed, 10V at almost full speed. Using a multimeter, I decide the driver circuit is probably OK. So, I test the resistance of the motor by itself. It reads 1 ohm which is really low even for a motor. According to this article they should read more like 47 ohms. So, I'm expecting that the motor may have an internal short.
