I think this part of the forum is not going to take off. Ebay has a lock on this end of things.

Yes or no to Free Run Stop? Inertia and stopping time is obviously the most critical aspect here.

The time it takes for an electric motor to come to a stop naturally depends on factors such as the inertia of the load, the motor size, and the operating conditions. In some cases, allowing the motor to stop freely may be acceptable if the stopping time is within safe limits.

Your brake will never fail if you don't use a brake at all. So it is a nice option if it is practical and safe.

Fanuc is a leading manufacturer of industrial robots and CNC systems, and it is consistently innovating and releasing new models to stay at the forefront of technology.

They regularly introduce improvements, enhanced features, and new capabilities in their products. So yes they are not only relevant but awesome. I go out of my way to steer toward Fanuc controls.

Thank you! Had ALARM 400 (OVERLOAD), simple problem and simple solution, turned out to be mechanical bind holding it back. Hint, keep your machines clean!

Toshiba VF-AS1 Alarms and Faults
possible causes and the associated remedy. Hopefully this alarm code list
Here is a general list of Toshiba AS1 alarms and fault codes. Included are will help guide you in your troubleshooting.

• OC1 / OC1P Description: Overcurrent during acceleration Causes:  The acceleration time ACC is too short, the V/F setting is improper, a restart signal is input to the rotating motor after a momentary stop, etc., a special motor (motor with a small impedance) is used, or manual torque boost ub is large.
  
  Remedy/Solutions:  Increase the acceleration time ACC,  Check the V/f parameter setting, Use UuS (Auto-restart) and UuC (Regenerative power ride-though control), Increase the carrier frequency CF,
  Decrease ub setting value, Decrease F50 (stall prevention level) to 130 as a guide, Increase CF (carrier frequency) setting value if it is set at lower value (2kHz or less), Check the cable and the motor for ground faults.
  
• OC2 / OC2P Description: Overcurrent during deceleration Causes: The deceleration time dEC is too short, or there is a possible ground fault
  
  
• OC3 / OC3P Description: Overcurrent during fixed speed Causes: The load fluctuates abruptly, the load is in an abnormal condition, or there is possibly a ground fault.
  
  
• OCA1 Description: U-Phase arm short-circuit Causes: a main circuit element is defective on U Phase
  
  
• OCA2 Description: V-Phase arm short-circuit Causes: a main circuit element is defective on V Phase
  
  
• OCA3 Description:: W-Phase arm short-circuit Causes: a main circuit element is defective on W Phase
  
  
• OCL Description: Loaded side overcurrent at start time Causes: The insulation of the output main circuit or motor is defective, The motor has too small impedance, The drive circuit board in the inverter was damaged.
  
  
• OCr Description: Dynamic braking element overcurrent 200v 55kW or larger, 400V-90kW or larger Causes: • PB-PA/* circuit is shorted, A resistor with resistance smaller than the minimum allowable resistance is connected, Parameter Pb was set to 1 or 2 without connecting regenerative brake or with wire disconnected (with dynamic braking).
  
  
• OH Description: Overheating Causes: The cooling fan does not rotate, The ambient temperature is too high, The vent is blocked up, A heat generating device is installed close to the inverter, The thermistor in the unit is disconnected.
  
  
• OH2 Description: Thermal trip (stop command from external device) Causes: An input signal is impressed at control input terminal PTG for optional add-on cards, A thermal trip command (input terminal function: 46 or 47) is issued by an external control device.
  
  
• OL1 Description: Inverter Overload  Causes: Rapid acceler on is operated, The DC braking amount is too large, The V/f setting is improper, A restart signal is input to the rotating motor after a momentary stop, The load is too large.
  
• OL2 Description: Motor Overload  Causes: The V/f parameter is improperly set, The motor is locked up, Low-speed operation is performed, An excessive load is applied to the motor during operation .
  
• OLr Description: Dynamic braking resistor overload  Causes: Rapid deceleration is operated, Dynamic braking is too large.
  
• OP1 Description: Overvoltage during acceleration  Causes: the input voltage fluctuates abrormaly, the power supply has a capacity of 500KVA or more, A power factor improvement capacitor is opened and closed, A system using a thyrister is connected to the same power distribution line, A restart signal is input to the stop. etc.
  
• OP2 Description: Overvoltage during deceleration  Causes: The deceleration time DEC is too short, The dynamic braking resistor has a considerably large resistance, Pb (Dynamic braking resistor) is OFF, Overvoltage limit operation F305 is OFF, The input voltage fluctuates abnormaly, The power supply has a capacity of 500kVA or more,  A power factor improvement capacitor is opened and closed, A system using a thyrister is connected to the same power distribution line.
  
• OP3 Description: Overvoltage during fixed speed operation  Causes: The input voltage fluctuates abnormally, The power supply has a capacity of 500kVA or more, A power factor improvement capacitor is opened and closed, A system using a thyrister is connected to the same power distribution line, The motor is in a regenetive state because the load causes the motor to run at a frequency higher than the inverter output frequency, The undervoltage detection level F625 is too low..
  
• Ot Description: Overtorque  Causes: Overtorque reaches to a detection level during operation, Stall prevention operation was performed continuously for a length of time longer than that set with F452 .
  
• UC Description: Low current  Causes: The outout current decreased to a low-current delecton level during operation.
  
• UP1 Description:  : Voltage drop in main circuit  Causes: The input voltage (in the main circuit) is too low, Momentary power failure occurs because undervoltage continues longer than undervoltage detection time F528.
  
• E Description: Emergency stop
  
  
• EEP1 Description: EEPROM error
  
  
• EEP2 Description:  Initial read error
  
  
• EEP3 Description:  Initial read error
  
  
• EF1 Description: Ground fault
  
  
• EF2 Description: Ground fault
  
  
• EEPH0 Description: Output phase failure
  
  
• Err1 Description: Input phase failure
  
  
• Err2 Description: Main Unit RAM fault
  
  
• Err3 Description: Main Unit ROM fault
  
  
• Err4 Description: CPU Fault
  
  
• Err5 Description: Interruption of operation command from external control device
  
  
• Err6 Description: Gate Array fault
  
  
• Err7 Description: Output current detector error
  
  
• Err8 Description: Optional unit fault
  
  
• Etn Description: Tuning Error
  
  
• Etn1 Description: tuning detection error
  
  
• Etn2 Description: Motor constant value error
  
  

This one is a work in progress, stand by...

Anybody else collect vintage meter movements? There's some cool stuff out there.

Toshiba H9 Drive Alarms

This is a list of the available user-notification codes of the EOI display and provides information that assists the user in the event that a Fault is incurred. The User Notification codes are displayed as an indication that a system function or system condition is active (i.e., ATN, DB, and DBON). The code is displayed on the EOI for the duration of the activation.

An Alarm is an indication that a Fault is imminent if existing operating conditions continue unchanged.

A Trip is a safety feature (the result of a Fault) that disables the H9 ASD system and removes the 3-phase power to the motor in the event that a subsystem of the ASD is malfunctioning, or one or more of the variables listed exceeds its normal range (time and/or magnitude). Included critical items in the trip list are: Current, Voltage, Speed, Temperature, Torque, or Load.

These alarms apply to Toshiba H9 ASD models: VT130H9U2035, VT130H9U2055, VT130H9U2080, VT130H9U2110, VT130H9U2160, VT130H9U2220, VT130H9U2270, VT130H9U2330, VT130H9U2400, VT130H9U2500, VT130H9U2600, VT130H9U2750, VT130H9U210K,VT130H9U212K, VT130H9U4055, VT130H9U4080, VT130H9U4110, VT130H9U4160, VT130H9U4220, VT130H9U4270, VT130H9U4330, VT130H9U4400, VT130H9U4500, VT130H9U4600, VT130H9U4750, VT130H9U410K, VT130H9U412K, VT130H9U415K, VT130H9U420K, VT130H9U425K, VT130H9U430K, VT130H9U435K, VT130H9U440K

• CM1 Comm1 Error -  Internal communications error - Caused by: Improperly programmed ASD, Improper communications settings, Improperly connected cables.
• CM2 Comm2 Error - External communications error - Caused by:  Improperly programmed ASD, Improper communications settings, Improperly connected cables.
• E Emergency Off -  Output signal from the ASD is terminated and a brake may be applied if so configured - Caused by: Stop|Reset pressed twice at the EOI, EOFF command received remotely, ASD reset required.
• MOFF Main Under-Voltage - Under-voltage condition at the 3-phase AC input to the ASD - Caused by: Low 3-phase commercial voltage
• OC Over-Current - ASD output current greater than F601 setting. - Caused by: Defective IGBT (U, V, or W), ASD output to the motor is connected incorrectly, ASD output phase-to-phase short, The ASD is starting into a spinning motor, Motor/machine jammed, Mechanical brake engaged while the ASD is starting or while running, Accel/Decel time is too short, Voltage Boost setting is too high, Load fluctuations, ASD operating at an elevated temperature
• OH Overheat - ASD ambient temperature excessive. - Caused by: ASD is operating at an elevated temperature, ASD is too close to heat-generating equipment, Cooling fan vent is obstructed (see Mounting the ASD on pg. 15 of the service manual), Cooling fan is inoperative, Internal thermistor is disconnected.
• OJ Timer -  Run-time counter exceeded - Caused by: Type Reset required; select Clear run timer
• OLI ASD Overload -  Load requirement in excess of the capability of the ASD. - Caused by:  The carrier frequency is too high, An excessive load, Acceleration time is too short, DC damping rate is set too high, The motor is starting into a spinning load after a momentary power failure, The ASD is improperly matched to the application.
• OLM Motor Overload -  Load requirement in excess of the capability of the motor. - Caused by: V/f parameter improperly set, Motor is locked, Continuous operation at low speed, The load is in excess of what the motor can deliver
• OLR Resistor Overload - Excessive current at the Dynamic Braking Resistor - Caused by: Deceleration time is too short, DBR configuration improperly set
• OP Over-Voltage - DC bus voltage exceeds specifications. - Caused by: ASD attempting to start into a spinning motor after a momentary power loss, Incoming commercial power is above the specified range, Decel time is too short,  Voltage spikes at the 3-phase input; install inductive filter, DBR required, DBR resistance value is too high, DBR function is turned off, Over-Voltage Stall feature is turned off, System is regenerating, Load instability, Disable the Ridethrough function (F302)
• OT Over-Torque - Torque requirement is in excess of the setting of F616 or F617 for a time longer than the setting of F618. - Caused by: ASD is not correctly matched to the application, F616 or F617 setting is too low, Obstructed load.
• POFF Control Under-Voltage - Under-voltage condition at the 5, 15, or the 24 VDC supply - Caused by: Defective Control board, Excessive load on power supply, Low input voltage.
• PtSt Reference Point - Two speed-reference frequency setpoint values are too close to each other - Caused by: Two speed reference frequency setpoints are too close to each other (increase the difference).
• UC Under-Current - With the Low-Current Trip (F610) parameter enabled, the output current of the ASD is below the level defined at F611 and remains there for a time longer than the setting of F612 - Caused by: Output current too low

Fanuc Series -0 Alarms and Troubleshooting

Here is some good info from the Fanuc service manual, hopefully helps you guys out. Following is a list of alarms on applicable Fanuc Series:

FANUC Series 0- TC, 0- TC, FANUC Series 0- MC, 0- MC, FANUC Series 0- TF, 0- TF, FANUC Series 0- MF, 0- MF, Series 0- C, FANUC Series 0- TTC, 0- TTC, FANUC Series 0- GCC, 0- GCC, FANUC Series 0- GSC, 0- GSC, FANUC Series 0- TD, 0- TD Series 0, FANUC Series 0- MD, 0- MD, Series 0- D, FANUC Series 0- GCD, 0- GCD, Series 0- D, FANUC Series 0- GSD, 0- GSD, Series 0- D, FANUC Series 0- TD II, 0- TD II, Series 0- D, FANUC Series 0- MD II, 0- MD II, Series 0- D II, FANUC Series 0- GCD II, 0- GCD II, Series 0- D II, FANUC Series 0- GSD II, 0- GSD II, FANUC Series 00- TC 00- TC, FANUC Series 00- MC, 00- MC Series 00- C, Series 00, FANUC Series 00- GCC, 00- GCC, FANUC Series 0- Mate TC, 0- Mate TC, FANUC Series 0- Mate, MC 0- Mate, MC Series 0- Mate, C Series 0- Mate, FANUC Series 0- Mate, MF 0- Mate MF

• POWER CANNOT BE SWITCHED ON - Check the LED on the input unit or power supply unit AI, If no power supply alarm is detected (the red "ALM" LED does not light, Check the input fuse of the input unit or power supply unit AI.
  
  Measure the voltage across the R and S terminals on the screw-on terminal strip of the input unit or at the connector CP1 of the power supply unit AI using a volt-ohm-milliammeter, and check whether 200 VAC is available. If the 200 VAC cannot be detected at connector CP1, check the corresponding circuit in the machine.
  
  If both the fuse and power supply voltage are normal, the printed--circuit board of the input unit or the power supply unit AI may be defective.
• NO MANUAL OPERATION NOR AUTOMATIC OPERATION CAN BE EXECUTED - Execute the following procedure when no manual nor automatic operation is done: Check whether position display shows correct position, Check CNC status display, Check CNC internal status using diagnostic function
• JOG OPERATION CANNOT BE DONE - Check whether position display is operating, Check CNC status display, Check internal status using Diagnostic funciton.
• HANDLE OPERATION CANNOT BE DONE - Check another manual operation (JOG) is accepted, Check CNC status display.
• AUTOMATIC OPERATION CANNOT BE DONE - Check manual operation is possible, Check the status of cycle start LED on machine operator's manual, Check status of CNC.
  
  When manual operation is either impossible, perform countermeasure, based on the previous item "Jog operation cannot be done". Confirm that a correct mode isselected according to the mode selectstatus of CNC status display. Also, by confirming the automatic operation status it is possible to identify cycle operation, feed hold and cycle stop state
• CYCLE START LED SIGNAL HAS TURNED OFF - After cycle operation is started, then stopped, check as follows: Confirm cycle start LED on machine operator's panel, Confirm CNC's diagnostic function.
• NO DISPLAY APPEARS ON THE SCREEN WHEN THE POWER IS SWITCHED ON
• ALARM 85 (READER/PUNCHER INTERFACE ALARM) Parameters on reader/puncher interface are not correct. Check the following setting data and parameters. External I/O device or host computer is faulty. I/O board is faulty. Cable between NC and I/O device is faulty. Parameters on reader/puncher interface are not correct, Check the appropriate setting data and parameters.
• ALARM 86 (READER/PUNCHER INTERFACE ALARM) Parameters on reader/puncher interface are not correct. Check the following setting data and parameters. External I/O device or host computer is faulty. I/O board is faulty. Cable between NC and I/O device is faulty. Parameters on reader/puncher interface are not correct, Check the appropriate setting data and parameters.
• ALARM 87 (READER/PUNCHER INTERFACE ALARM) Parameters on reader/puncher interface are not correct. Check the following setting data and parameters. External I/O device or host computer is faulty. I/O board is faulty. Cable between NC and I/O device is faulty. Parameters on reader/puncher interface are not correct, Check the appropriate setting data and parameters.
• REFERENCE POSITION DEVIATES
• ALARM 90 (REFERENCE POSITION RETURN IS ABNORMAL) The CNC received one rotation signal at least one time when the axis is moving to the reference position at a speed higher than a speed equivalent
  to 128 pulses of position error amount(DGN800 to 807), note: When a pulse coder is used as the detection of the absolute position, the reference point can be established after the motor turns more than one rotation with the battery connected.
• ALARM 3n0 (REQUEST FOR REFERENCE POSITION RETURN) Absolute position data in the serial pulse coder was lost. (This alarm will be generated when serial pulse coder is exchanged or position feedback signal cable of the serial pulse coder is disconnected)
• ALARM 3n1 (ABSOLUTE PULSE CODER IS FAULTY) Absolute pulse coder, cable or servo module is faulty. Jiggle the feedback cable leading from the servomotor to the axis card. Note whether an alarm occurs. If an alarm occurs, replace the cable or replace the axis cable.
• ALARM 3n2 (ABSOLUTE PULSE CODER IS FAULTY) Absolute pulse coder, cable or servo module is faulty. Jiggle the feedback cable leading from the servomotor to the axis card. Note whether an alarm occurs. If an alarm occurs, replace the cable or replace the axis cable.
• ALARM 3n3 (ABSOLUTE PULSE CODER IS FAULTY) Absolute pulse coder, cable or servo module is faulty. Jiggle the feedback cable leading from the servomotor to the axis card. Note whether an alarm occurs. If an alarm occurs, replace the cable or replace the axis cable.
• ALARM 3n4 (ABSOLUTE PULSE CODER IS FAULTY) Absolute pulse coder, cable or servo module is faulty. Jiggle the feedback cable leading from the servomotor to the axis card. Note whether an alarm occurs. If an alarm occurs, replace the cable or replace the axis cable.
• ALARM 3n5 (ABSOLUTE PULSE CODER IS FAULTY) Absolute pulse coder, cable or servo module is faulty. Jiggle the feedback cable leading from the servomotor to the axis card. Note whether an alarm occurs. If an alarm occurs, replace the cable or replace the axis cable.
• ALARM 3N6 (ABSOLUTE PULSE CODER IS FAULTY) Absolute pulse coder, cable or servo module is faulty. Jiggle the feedback cable leading from the servomotor to the axis card. Note whether an alarm occurs. If an alarm occurs, replace the cable or replace the axis cable.
• ALARM 3n7 (ABSOLUTE PULSE CODER BATTERY IS LOW) This alarm is generated when absolute pulse coder battery becomes low. Replace the batteries in the battery box connected to the connector of axis
  cards (CPA9 for the 1st to 4th axis cards, CPA10 for the 5th/6th axis card, and CPA11 for the 7th/8th axis card) When a type B axis board is being used with a built-in absolute pulse coder and an "a" or "b" series amplifier, the battery is installed in the servo amplifier. In such a case, replace the battery as described in the appropriate manual supplied with the servo amplifier.
• ALARM 3n8 (ABSOLUTE PULSE CODER BATTERY IS LOW)  This alarm is generated when absolute pulse coder battery becomes low. Replace the batteries in the battery box connected to the connector of axis
  cards (CPA9 for the 1st to 4th axis cards, CPA10 for the 5th/6th axis card, and CPA11 for the 7th/8th axis card) When a type B axis board is being used with a built-in absolute pulse coder and an "a" or "b" series amplifier, the battery is installed in the servo amplifier. In such a case, replace the battery as described in the appropriate manual supplied with the servo amplifier.
• ALARM 3n9 (SERIAL PULSE CODER IS ABNORMAL) An error is generated in the control section of the serial pulse coder
• ALARM 400 (OVERLOAD) Amplifier or overheat of motor is detected. Confirm the detail by the diagnostic function of CNC.
• ALARM 401 (*DRDY SIGNAL TURNED OFF) Servo amplifier is not turned on or it turned off during operation.
• ALARM 402 (OVERLOAD)  Amplifier or overheat of motor is detected. Confirm the detail by the diagnostic function of CNC.
• ALARM 403 (*DRDY SIGNAL TURNED OFF) Servo amplifier is not turned on or it turned off during operation.
• ALARM 404 (*DRDY SIGNAL TURNED ON) DRDY signal is turned on before MCON signal is turned on. Or DRDY is not turned off after MCON signal is turned off. Possible servo amplifier is faulty, between servo amplifier and axis card is faulty, axis card is faulty.
• ALARM 405 (*DRDY SIGNAL TURNED ON) DRDY signal is turned on before MCON signal is turned on. Or DRDY is not turned off after MCON signal is turned off. Possible servo amplifier is faulty, between servo amplifier and axis card is faulty, axis card is faulty.
• ALARM 406 (OVERLOAD)  Amplifier or overheat of motor is detected. Confirm the detail by the diagnostic function of CNC.
• ALARM 490 (OVERLOAD)  Amplifier or overheat of motor is detected. Confirm the detail by the diagnostic function of CNC.
• ALARM 491 (*DRDY SIGNAL TURNED OFF) Servo amplifier is not turned on or it turned off during operation.
• ALARM 4n0 (EXCESSIVE POSITION ERROR AMOUNT DURING STOP)
• ALARM 4n1 (EXCESSIVE POSITION ERROR DURING MOVE) Position error amount during movement (DGN 800 to 807) execeeds a value set by parameter 504 to 507, 639, 640, 7504, 7505.
• ALARM 4n4 (DIGITAL SERVO SYSTEM IS ABNORMAL)
• ALARM 4n6 (DISCONNECTION ALARM) Position detection signal line is disconnected or short-circuited.
• ALARM 4n7 (DIGITAL SERVO SYSTEM IS ABNORMAL) Digital servo parameters are abnormal or are set incorrectly. Confirm the setting value of the following parameters: PRM 8n20 : Motor format number PRM 8n22 : Motor rotation direction PRM 8n23 : Number of pulses of velocity feedback PRM 8n24 : Number of pulses of position feedback PRM 0269 to 0274 : Servo axis number PRM 8n84 : Flexible feed gear ratio PRM 8n85 : Flexible feed gear ratio
• ALARM 700 (OVERHEAT AT CONTROL SIDE) Because an ambient temperature of the control unit becomes high, a thermostat mounted on the back panel of NC functions and informs an alarm
• ALARM 704 (SPINDLE SPEED FLUCTUATION DETECTION ALARM) This alarm indicates that the spindle speed has changed abnormally due to the load.
• ALARM 408 (THE SPINDLE SERIAL LINK DOES NOT START NORMALLY.) : Indicates that, in a system using serial spindles, the spindle amplifier does not start normally when power is applied. This alarm will not occur once the system (including the spindle control unit) has started. It can occur before the system starts during power turn-on processing. Once the system has started, an error is indicated as system alarm 945.
• ALARM 409 (SPINDLE ALARM) This alarm indicates, to the CNC, that in a system with serial spindles, an alarm has occurred in the spindle unit. The alarm is described using the AL-XX (where XX is a number) format Indicated on the spindle amplifier display. Setting bit 7 of parameter No. 0397 to 1 enables the display of the alarm number from the spindle on the alarm screen. This alarm is intended to indicate a failure in the spindle control unit. It is detailed below. The spindle should be repaired according to the procedure described for each alarm.
• ALARM 998 (ROM PARITY ERROR) A ROM parity error has occurred.
• ALARM 910 (RAM PARITY ERRORS) These alarms indicate RAM parity errors. RAM is provided with a check bit (parity bit). When data is written to RAM, the check bit is also written to the RAM by either setting it to 1 or resetting it to 0 so that the total number of 1 bits in the data, including the check bit, is even or odd. When the data is read from RAM, the check bit is used to ensure that the read data is correct.
• ALARM 911 (RAM PARITY ERRORS)
• ALARM 912 (RAM PARITY ERRORS)
• ALARM 913 (RAM PARITY ERRORS)
• ALARM 914 (RAM PARITY ERRORS)
• ALARM 915 (RAM PARITY ERRORS)
• ALARM 916 (RAM PARITY ERRORS)
• ALARM 920 (WATCH DOG OR RAM PARITY) The timer used to monitor the operation of CPU is called the watch dog timer. The CPU resets timer time every time a constant time has passed. When an error occurs in CPU or peripheral device, timer is not reset but the alarm is informed.
• ALARM 921 (WATCH DOG OR RAM PARITY) The timer used to monitor the operation of CPU is called the watch dog timer. The CPU resets timer time every time a constant time has passed. When an error occurs in CPU or peripheral device, timer is not reset but the alarm is informed.
• ALARM 922 (WATCH DOG OR RAM PARITY) The timer used to monitor the operation of CPU is called the watch dog timer. The CPU resets timer time every time a constant time has passed. When an error occurs in CPU or peripheral device, timer is not reset but the alarm is informed.
• ALARM 941 (INCORRECTLY INSTALLED MEMORY PRINTED--CIRCUIT BOARD) This alarm indicates the poor connection of a memory printed circuit board. Check that all connections are secure.
• ALARM 930 (CPU ERROR) CPU error (abnormal interrupt) has generated. Main CPU board is faulty An interrupt which will not occur during usual operation has generated. Peripheral circuit of the CPU may be abnormal. Change the main CPU board. If operation is performed normally by power off and on, noise may be a cause.
• ALARM 945 (SERIAL SPINDLE COMMUNICATION ERRORS)
• ALARM 946 (SERIAL SPINDLE COMMUNICATION ERRORS)
• ALARM 960 (SUB CPU ERROR) Sub-CPU printed circuit board defective. An interrupt that would not occur under a usual condition occurred. It is likely that a CPU peripheral circuit malfunctioned. Replace the sub-CPU printed circuit board. If a normal operation can be resumed by turning the power off and on again, the malfunction may have occurred due to noise
• ALARM 950 (BLOWN FUSE) The +24E fuse has blown. An overcurrent has flowed through the +24E line, which is a 24V line used for the I/O printed circuit board and machine power magnetics circuit. There may be a short circuit between the 24V line and 0V in the machine or I/O cable. After removing the cause, replace fuse in the power supply unit.

Yaskawa drives are somewhat popular,  Yaskawa Site has a bunch of new products listed.

These drives were made by Electromotive Systems, Inc. (ESI)

They are a company based in Milwaukee, Wisconsin. ESI specializes in providing advanced electrical and electronic control systems for various industries, including locomotive and marine propulsion, industrial automation, crane control, and power generation. They offer a range of products and solutions, including motor control systems, electronic controls, power conversion equipment, and related services.

Not sure these drives are still around.