For information on ESD protection, please see: HERE

Spindle Control Components

	Inductor – Murata – BLM21PG221SH1D
	Spindle 0–10 V Output TVS Protection Diode – NXP – PESD5Z12
	Spindle Clockwise (CW) TVS Protection Diode – NXP – PESD5Z5.0
	Spindle Counter Clockwise (CCW) TVS Protection Diode – NXP – PESD5Z5.0
	Spindle Clockwise Diode – Leshan Radio – LBAS21HT1G
	Spindle Counter Clockwise Diode – Leshan Radio – LBAS21HT1G

Spindle Control Output Pin 2 & 3 Testing

Before performing component-level testing, follow the spindle troubleshooting process in the MASSO documentation: 

https://docs.masso.com.au/getting-started-guides/troubleshooting-guides/vfd_spindle

If the Optocoupler IC tests faulty and replacement does not resolve the issue, the fault is likely in the components driving the Optocoupler IC.

	Clockwise
	Counter Clockwise
	Protection Diode PESD5Z5.0 - This diode protects against static discharges and voltages applied to the spindle control output 2
	Protection Diode PESD5Z5.0 - This diode protects against static discharges and voltages applied to the spindle control output 3

The Optocoupler ICs are driven directly from spindle control outputs 2 and 3.

If these outputs are damaged, the Optocouplers will not operate.

Testing Spindle Control Pin 2 (Clockwise)

Use this test when Clockwise rotation is not working.

Voltage Test

1. Turn MASSO ON.

2. Ensure nothing is connected to spindle control pin 2.

3. Go to the F1 screen and press the Spindle CW button.

4. Measure the voltage between Spindle Control Pin 2 and MASSO GND.

Expected result:

• 3 V nominal

If the voltage is below 2 V, inspect the protection diode.

Protection Diode – PESD5Z5.0 (Pin 2)

This diode protects spindle control output 2 from static discharge and external voltages.

Diode Test Procedure

1. Turn MASSO OFF and leave it off for testing.

2. Disconnect all wiring from the output under test.

3. Set the multimeter to Diode Test mode.

Test 1

• Black probe to MASSO GND

• Red probe to Spindle Control Pin 2

• Expected reading: ~1.4 V

Test 2

• Red probe to MASSO GND

• Black probe to Spindle Control Pin 2

• Expected reading: ~0.7 V

Note: A reading of 0 V indicates the diode is shorted to GND.

If unsure, compare readings with Spindle Control Pin 3.

If the diode fails testing, it can be removed from the board.
Normal output operation will resume if this is the only fault.

The protection diode is not required for normal operation.
It may be replaced or left out. If left out, ESD protection is lost for that output. 

Testing Spindle Control Pin 3 (Counter Clockwise)

Use this test when Counter Clockwise rotation is not working.

Voltage Test

1. Turn MASSO ON.

2. Ensure nothing is connected to spindle control pin 3.

3. Go to the F1 screen and press the Spindle CCW button.

4. Measure the voltage between Spindle Control Pin 3 and MASSO GND.

Expected result:

• 3 V nominal

If the voltage is below 2 V, inspect the protection diode.

Protection Diode – PESD5Z5.0 (Pin 3)

This diode protects spindle control output 3 from static discharge and external voltages.

Diode Test Procedure

1. Turn MASSO OFF and leave it off for testing.

2. Disconnect all wiring from the output under test.

3. Set the multimeter to Diode Test mode.

Test 1

• Black probe to MASSO GND

• Red probe to Spindle Control Pin 3

• Expected reading: ~1.4 V

Test 2

• Red probe to MASSO GND

• Black probe to Spindle Control Pin 3

• Expected reading: ~0.7 V

Note: A reading of 0 V indicates the diode is shorted to GND.

If unsure, compare readings with Spindle Control Pin 2.

If the diode fails testing, it can be removed from the board to restore operation.
The diode may be replaced or left out. Leaving it out removes ESD protection.