Emerson CT inverter common fault code and maintenance method - Database & Sql Blog Articles

1. Current detection failure (e.g., E019, E001):

(1) The control board Q1 (15050026) is damaged.

(2) 7840 IC is faulty: When the inverter is powered on, use a DC meter to measure between 5V and 6V, 7V, 8V respectively. If the readings are 2.5, 2.5, 5V, it's normal; otherwise, the 7840 is bad.

(3) The small board is faulty: When the inverter is on, connect the black lead to the 5th pin of 7840 and the red lead to the small board. The left pins should read 2.5, 2.5, 2.5, 3.4, 1.5, 0, 1.6. If not, the small board is bad. Replace the three small ICs (39030024LMV393). If still not working, replace the small board entirely.

2. Display POFF:

The driver board's POFF should be around 2.6–2.7V. If measured at 1.9V, check R51, R52, C36, C37. Most likely, one of these components is bad, especially electrolytic capacitors. POFF only occurs when the motor is running, and the driver board’s transformer might be damaged.

3. Faulty snubber resistor:

The snubber resistor and filter bulk capacitor work together. If one is bad, the other may also be faulty. A snubber resistor can fail due to a relay that doesn’t engage (bad relay or faulty control board). For single-phase 220V inverters, if there's no display or a short circuit, it could mean the user connected 380V power. Check the control board for bus voltage changes from 310V to 540V. If so, the IPM rectifier bridge is likely broken, along with the filter capacitor (bulging or hardened top). Replacing the IPM without checking the capacitor may cause further damage. If you hear a “pop” sound after replacement, power off immediately.

4. Unstable display:

Display flickers or disappears, fan stops, and voltage drops to 12V. This usually indicates a faulty U1 thick film. E015 fault: Power-on indicator lights, but keyboard and fan don’t turn on—fan shorted.

5. No braking:

Brake pipes for 01180099, 01180100, 01180113, and 01180114 are not inside the IPM. Inverters may report no braking after stopping. After replacing the IPM, check the brake circuit: brake optocoupler, brake transistor (check its freewheeling diode, which should be ~0.37V), gate resistance (~100Ω). After repair, TD900F093 should show 150, and when measuring P(+) to PB, the voltage should be 17–30V. For TD3200F133=150, DC voltage should be 270–350V for proper braking.

6. Blown rectifier bridge:

If some rectifier bridges are damaged while the inverter bridges are fine, it may be due to arcing between positive and negative busbars. High humidity often causes water droplets between terminals or between positive and radiator, leading to a short. Insulation must be replaced to prevent re-blowing. Another cause is a shorted filter capacitor (bulged or hardened top), which must be replaced.

7. Machine humming:

Fast/slow fan with no display. Usually caused by a shorted control board. Remove the board and power on again. If still humming, the thick film or nearby components may be faulty. For example, R56 on the TD1000 large volume resistor (27 ohms) being much higher than normal. The switching power supply may not be working, causing oscillation but a short in the rear circuit. If no voltage at all, the thick film or 2844 chip is likely bad.

8. Weak fan speed:

D6 breakdown on EV1000. Fault code 8888: FECDF21U1 board U8 is faulty, with visible cracks. On EV1000 models like 01180128, a load stop report 8888 may indicate poor transformer inductance or insufficient insulation between primary and secondary coils of PC9.

9. Fault code 8888: drive optocoupler shorted.

10. EV1000 large volume: original fault was a short, then no output or E019. Often U9 is faulty. Sometimes Q2 is bad when there's no output.

11. EV1000 small volume: original fault was a short, no output after repair. Often R13 is bad. Always check if R13 is 10 ohms during repair.

12. TD3000 power-on display POFF:

Check if the driver board’s CVD voltage is 2.5–2.8V. Check IU, IV, IW voltages (current detection circuit). Ensure VREF reference voltage (T1 regulator U24 at 2.5V) is normal. If all correct, reprogram two DSP programs. After erasing, wait a few seconds before writing to avoid DSP failure.

After repair, verify the following to reduce risk of short:

Connect DC meter red to "ten", black to UVW. For TD900/TD3200 single-phase: 310V; three-phase: 540V. For TD1000/TD3000/EV1000/EV2000: 5–10V. If not correct, do not press. Stop corresponding optocouplers and diodes, repeat until voltage is right.

13. Display E010:

Power-on display E010: Hall sensor is faulty. If the inverter is on and E010 appears, the current detection circuit is faulty. No current output yet, but detected. Small machines often have TL082C issues; high-power machines often have Hall sensors bad. To determine which phase has a problem, test IU, IV, IW with mv file. If any reading is +10 or -10, that phase is faulty.

Example: IV = 1000mV → V phase Hall is bad. If E010 appears as soon as operation starts, module may be bad. To check which phase, power on and measure UVW with DC meter. Normal should be 5–10V. If one phase is much higher, that module is faulty.

14. Output imbalance:

If IPM and optocoupler are good, the optocoupler may have degraded. Replace it. Control board or IPM may also be faulty. To determine if upper or lower bridge is bad, power on and press start. Measure UVW with DC meter. Normal should be 210V. If one phase is 0, lower bridge is bad. Measure UVW with black to "-", normal 210V. If one phase is 0, upper bridge is bad.

15. Insulation or withstand voltage:

(1) Heat sink not flat, IGBT bad. (2) Foreign matter (like tin slag) in silicone grease damages IGBT. (3) Brake pipe insulation film broken or ceramic cracked. (4) High-power machine insulation column defective. (5) Grounding capacitor on board is faulty. One pair of secondary withstand voltage: Drive plate optocoupler is poor.

16. EV2000 health disk: Display 4 8 and all lights bright (darker): Solder joint on CN1 second row, second foot from left.

17. Control panel no display repair steps:

(1) Check voltage. (2) Test crystal oscillator. (3) Check reset signal. (4) Rewrite software.

18. Troubleshooting POFF or E019:

After aging FECD machine, PQC test shows POFF or E019. U1 feels slightly hot. Replace U1. Cannot write software: FECD control board U1U2U16U301 cannot write. Found 5V short circuit in test tool, but multimeter shows normal resistance. Many devices removed, long analysis. Now installed U329. Repair process: don't rush to measure, change parts first. Observe front/back, close/far, solder joints, tin, reversed, wrong components.

19. EV2000 control board troubleshooting:

Power-on POFF: Measure 76, 77 or C19 of U1, C18 normally 1.6V. If normal, DSP is bad. If low (e.g., 3.8V, 0.5V), U19, U20 is bad.

No display: 3 feet of 3.3VQ10 and GND resistance 0.6K. DSP is bad. No display: U24 8th pin only 1.5V, should be 2.5V. L3 unreachable, L3 is bad. Otherwise, DSP is bad.

No display: Test U17-LM324 4 and 11 feet (+-15V) shorted. Power on LM324, found U17 and U18 slightly hot, no short after removal. U17 and U18 are bad.

No display: 5V short. U6 is bad. E004: Measure 76, 77 or C19 of U1, C18 is 3.8V. Normally 1.6V, U19, U20 is bad.

One press to run: U5, U9 is bad. VRF no 10V: U42, C107, C108 is bad.

E010: Upper tooling test U-light always on: U9 is bad. BRAKE lamp always on, relay K1 ringing: U6 is bad.

E019: Voltage of 8th pin of ICU19, U20, U21 (IU, IV, IW) is 0.34, 0.40, 6.46 → U21 is bad.

20. EV2000 power-on keyboard 4 8 plus 5 lights flash: Control board U8 is bad.

EV1000 small volume control board 03025856: No display. Test CN3 6-pin (SPISIMO-OUT) voltage 0V (should be 5V). Pin corresponds to U4 16-pin, 4-pin to DSP 21-pin (3.3V). Measured 0V → U1-DSP is bad. Frequency of EV1000 size and volume control board cannot be lowered (50HZ unchanged): L8 is soldered or bumped.

TD900 small volume frequency less than 50HZ, about 49.80: D10 reference drift, 5.1V regulator tube is bad.

TD1000 small volume control panel 03023847: E001 → U7 is bad.

TD3000 control board: Operation mode changes after power-on: E016, U13 EEPROM sometimes bad when changing mode.

TD3200 control panel: POFF appears when changing model. Factory parameters restored: E028. Before sending for repair, 93-pin RS1 signal of DSP changed to R19 via U19, U11 changed to RSEEPROM signal to U4. R19 cracked (not visible), EEPROM cannot reset.

21. All control board software programming:

(1) No power (110 appears): (A) Short circuit. (B) Crystal oscillator not vibrating (normal power-on voltage: 3.3V, frequency output terminal 1.6V. If wrong, oscillator is bad).

(2) Can’t write software (appears 113, 114): Generally DSP is bad.