Long Live an old Shopbot!

Long Live an old Shopbot!

Certainly like any good Shopbot owner I'm trying to squeeze the last bit of life out of every piece of this fantastic Workhorse of a tool. My perhaps 2001 PRT has always stalled in the Y direction after cutting 5 or 10 sheets of three quarter inch particle board. We basically figured out that was due to dull router bits. But over the past 3 or 4 months the Y carriage has been visibly shaking, wiggling, jerking and pulsating while cutting. And then stalling in the y direction with a brand-new bit on its first sheet of three-quarter inch particleboard after completing a little over half of its toolpath.

So here comes a thousand stupid unanswerable questions.

I have cleaned, lubed, readjusted, loosened, tightened, checked, every moving mechanical part on the machine. Swapped X & Y Motors, checked pinon tightness' swapped X and Y and Z channels, replaced one of the motor control wires and checked all of the rest of the wago wiring connections all with only minor improvements to its condition.

Some long long time ago I blew up the X2 motor Channel and purchased 15 of the a3955sb control chips. At the time I just switched my X2 wire to the A channel and moved on. So this time I decided to repair the X2 Channel and while testing with my meter I blew up one of the chips on the Y Channel. So I have now replaced the four chips that are needed for the X2 and the Y channels. And now LEDs on those two channels do not light up, ever, and those two channels will control the motor but the motor makes a screaming, crying, gurgling, sound that randomly gets louder and quieter.

I have a meter and an oscilloscope what should I test for?

And yes I have been running it without those protection diodes for over 4 years without any problems.

And yes with all the graphics programs I have in house I used Microsoft Paint for the "Illustrated" control board picture.