Yes I still use the console.
The IC has a very strange power, like 0v for 95% of time and then a 5V spike. Very regular, but it should be a flat 5V.

That could well be your problem!

 

I've got a MC2100ELS-18W where IGBT and thyristor were swapped. Afterwards, the motor lacked torque, speed control was erratic, and the over-current kept tripping. I suspected R63 but this tests fine out of circuit with a meter and a bench supply.

I'm now trying to test it on my bench with -
1) An arduino connected to Gnd and 5V on HD9, and LED pin of it connected to PWM on HD2 via a 300ohm resistor.
2) A 240V light bulb connected to the motor terminals.
3) Code doing -
void loop() {
digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level)
delay(30); // wait for a second
digitalWrite(LED_BUILTIN, LOW); // turn the LED off by making the voltage LOW
delay(20); // wait for a second
}

The Arduino LED blinks, and I see a voltage (0.8V on my meter, but it's PWM) on the opto pin, but the LED on the MC2100 doesn't do anything.

I've tried tweaking the 2nd delay up and down a little but it doesn't help.

What am I doing wrong?

 

Are you using a 20Hz PWM into pin 4 of HD2?
Also check the input current to the Opto series resistor, the on board one is very low value and requires external limiting.
I made my own 20 hz generator, there is also these: avaialable:

 

Thanks, yes 20Hz, and it's now working better. The board seems to need the PWM after switch on and it ignores the signal if it's there from start up.

My light bulb is now turning on dimly (and fades up/down as I connect and disconnect PWM) but the LED is still off. I know that +5V2 is present on HD6, and I'm told the LED was working in the machine but showing over current.

 

Well, isn't this project cursed, the little red LED was dead!

It's driving my 60W bulb with happy red LED flashing, so I guess the over-current it was showing in the machine is a real over-current.

 

Here is my IGBT gate drive signal. A nice strong drive, but an odd 25Mhz ripple/ring to it.