Part No.: 9705253032 (TR ASSY)
Purpose: To verify electrical integrity and signal exchange between the Control PCB and TR PCB (IPM Drive & Power Section) in Fujitsu VRF J-Series outdoor units.
Check Point 1: Circuit Connection
Inspect all wiring and connector positions:
CN301 (IPM DRIVE)
Pin 1: Brown – DC +5.0 V
Pin 2: Red – GND
Pin 3: Orange – Lo (signal line +DC5 V)
CN302 (IPM POWER) – Power link from Control PCB to TR PCB.
Ensure correct seating of connectors CN14, CN16, and CN302 between Control PCB and Transistor PCB.
Check Point 2: Control PCB and TR PCB Voltage Verification
1. Check Power Supply from Control PCB to IPM
Measure at CN16 (Control PCB).
Expected: DC +15 V between terminals 1–2.
If no voltage is present → Replace Control PCB.
2. Check TR PCB Supply Voltage
Disconnect CN14 between Control PCB and TR PCB.
Measure at TR PCB side (CN14 connector):
Expected: DC +5 V between terminals (1–2–3).
Check Point 3: Resistance Verification (IPM Output Stage)
Use a multimeter in resistance mode to test between the P/N terminals and U–V–W compressor outputs.
| Terminal | Between | Normal Resistance Value |
|---|---|---|
| P (+) | U (–), V (–), W (–) | 14 – 15 Ω |
| P (+) | N (–) | ∞ Ω |
| N (+) | U (–), V (–), W (–) | 14 – 15 Ω |
| N (+) | P (–) | ∞ Ω |
⚠ Abnormal reading (0 Ω or very low) indicates a shorted IPM transistor, requiring TR PCB replacement.
Check Point 4: Insulation Verification
Confirm insulation resistance between power terminals (P–N) and output terminals (U–V–W).
Expected: 1 MΩ or greater.
Low resistance indicates shorting or moisture contamination in PCB.
Summary of Key Readings
| Test Type | Terminal(s) | Expected Reading | Action if Abnormal |
|---|---|---|---|
| Supply Voltage | CN16 (Control PCB) | +15 V DC | Replace Control PCB |
| Signal Voltage | CN14 (TR PCB) | +5 V DC | Replace TR PCB |
| IPM Resistance | P–U/V/W | 14 – 15 Ω | Replace TR PCB |
| Insulation | Any–Earth | ≥ 1 MΩ | Dry/replace TR PCB |
