retrofit Bridgeport Prototrak Plus

Glad to hear you are having some success. Congratulations!
Don't get discouraged.

Now to make it move!

Today I unplugged the "y" wire set from power supply amplifier preparing to apply 1.5 vdc (battery) to TB5 (Drive 1), no connection was made to the battery, so as if that side was not connected to power supply on the control voltage side. As soon as I released the e-stop (as to allow power to the power supply for 1st time) a few sparks flu, and some smoke before I could reset e-stop, upon close inspection it appears the resistor has been cooked, the other one looks ok. I can get the numbers from the other one if that will help find a replacement.

Edit: the more I look at this part that is bad, it appears to be on the "x", the one side still connected. The circuit board is on the bottom of what looks to be a capacitor.

That is correct, the very 1st time. The "x" axis is the one that is bad, the "y" axis was getting ready to apply a 1.5 volt current too, was un-plugged from power supply. I have seen repairs on electronics where the component was cut in half and gently bent those existing wires up, twisted new component on soldered so the circuit board was not at risk of secondary heat damage. I need help identifying an replacement component, will shoot close up of good one if it will help.

Edit: Has the 7i77 card been compromised as well? Only killed one side, so half way there.

That resistor may not be the only thing damaged.

The better question is, why did it go poof? Was it a problem with the amp (not likely as it was working with the old system), or was something connected incorrectly, and killed it?
And what do you need to do to prevent it from happening again?

The 7i77 is unlikely to have been hurt unless you really had the wiring goofed up, and connected AC power or high voltage to it.

Maybe you could draw us a diagram of how you had the amp wired.

Is this ok for diagram of the components, there is a ground wire to all the pieces not shown other than the plugs. The left side is the plugs for the encoders going to the drives. The center is labeled TB3, connections 1 thru 6; 7 and 8 are open on encoders 0 and 1. The right is the power supply with separate heavy wires going to the drives and the light control wires going to TB5. If this is not acceptable please make comments so I may tweak it.

In your drawing, is what your calling the "Power Supply" the white box that has the amps in?
Maybe a photo of what you have going on might be better.

I do think you would have been better off not messing with anything in the big black box and just wired up a connector to the DB25 port on the outside of that to the 7i77.

You are correct these pics may be better info.

At the bottom center is a small gray cable with rectangle red plug going in to the side of aluminum case, this is P3 and P4, on other side is same for "x" P1 and P2


Can just see red plug under white wire.


The light blue thing is the capacitor with the dead part on the right side, centered top to bottom; labeled R1 on circuit board


In the background you see the 7i77 card with plugs to encoders

Edit: There are 2 of them, the other is to the left of the one that blown, on the end of the blue capacitor.

Many thanks