Troubleshooting Guide: Action-Based Categories

(1) No Action, No Display

① Turn off power. Use a multimeter (ohm setting) to check for shorts between AC220V and DC lines, between different DC voltages, and between DC lines and the machine chassis.

② Turn on power. Use the multimeter (30V DC setting) to check if the power supply or DC converter is outputting power. If not, replace the power supply or DC converter.

③ If power is normal, check if the main CPU is working (LED1 should blink to indicate normal operation). If not, replace the main CPU board or reprogram it.

④ If the main CPU is working (only LED1 blinking means it’s working but not communicating with the MMI display), check RS232 communication.

⑤ If the RS232 cable is okay, check if the MMI display is working (its CPU’s LED1 should blink). If not, replace the MMI CPU board or reprogram it.

(2) No Action, But Display Works

① Check if power cables are connected properly.

② Check all sockets for good contact.

③ See if the main CPU in the electrical box is working (red LED1 should blink, and green LED2 should also blink — red means CPU is working, green means communication with MMI is successful).

④ Use a multimeter (DC 30V and 120V settings) to check power supply outputs: controller power, VLV32 power, PH24V, and H38V connectors.

⑤ Check if manual action signals are reaching the computer (check if action, pressure, flow are displayed). If not, inspect the control panel wiring for shorts or breaks.

⑥ If signals are displayed but there’s still no action, check the directional valve output board and ammeter:

a. If display and ammeter work but output board doesn’t: Check H24V and HCOM. If okay and sockets are fine, replace the output board first, then the main CPU. You can also use the test screen to check each output point.

b. If display and valve work but ammeter doesn’t: Check if H38V reaches the PCB. If yes, unplug the MOLEX-4P wire and use the multimeter (RX10 setting) to check resistance across the proportional valve to the DA board (should be very low). If not, check wiring. If wiring is okay, replace the main CPU (watch polarity!).

(3) Action Works, But No Display

① Check if MMI +24V power is normal (should be 23.5–24.5V).

② Check if CPU board is working (LED1 blinking). If yes, replace the LCD module or high-voltage board.

③ If MMI CPU isn’t working, replace the MMI CPU board.

(4) Single Action Not Working

① First, make sure settings are correct: pressure, flow, time, count, function, position.

② Check if the screen shows action pressure and flow:

a. If yes: Refer to section (2) for checks.

b. If no: Check control panel wiring and action settings.

c. If pressure/flow show zero: Use the test screen to check limit switches. Manually trigger all related switches to see if abnormal signals are detected. Unplug the cable from the I/O board — if the signal remains, the I/O board is faulty; if not, the limit switch wiring is faulty.

③ Common manual action failures:

a. Can’t close mold: Ejector not retracted, safety door open, door switch failed, high mold close pressure, end-of-close failed, parameter error, core setting error.

b. Can’t open mold: Open-end switch stuck ON, parameter error.

c. Can’t eject: Eject advance/return failed, or eject count set to zero.

d. No auto injection: Temperature not reached, barrel advance failed.

e. Can’t melt: Temperature not reached, melt-end switch failed.

f. No auto threading: Threading sensor failed.

g. Can’t adjust mold: Adjustment function off, sensor error, parameter error.

h. No cooling: Melting time too long, increase cooling time.

Try slow manual movement in adjustment mode first, then verify screen settings.