On 02/08/2017 10:51 AM, Leon Fisk wrote:
It has decent interconnection stuff but just block diagrams for the
main and micro boards. Even with the microprocessor board disconnected
I can't get the wire drive to work. They were sold with manual knobs
(250) and with a Microprocessor/LCD display (250MP). The latter has
menus push-buttons, cool features. This is what I'm working on. Wanted
to prove to myself that the main board was okay. In theory it should
work with just a few jumpers and resistors. Most of it does, except the
wire drive. If I can get it working this way I'll go back to seeing why
the micro board seems to be dead. If I can't figure out the micro board
I may just rebuild it as the simple analog version. That would still be
a nice MIG machine.

I don't have the tech manual, but if you follow the traces on the main
board for the motor output back to the motor driver, It is a good bet
that the power device that drives the motor is toasted. There might be
some kind of interlock on it, but usually the highest power handling
device in a circuit is the first thing to fail. You can do a lot of
reverse engineering with manufacturer data sheets for the parts in the
circuit.

Look at power supply voltages around the driver circuit. If they look
sane, and you can see all the inputs to the circuits (from the data
sheets) behaving in a way that makes sense, I would swap the output devices.

Good Luck,
BobH