PANASONIC PT-50LC14
Service Manual

How to solve the problem indicated by the Error Indication of LED
(All symptom is that Lamp turns off or Lamp does not light up) Note: Before performing the troubleshooting, confirm that all connector cables in the unit are connected to connectors correctly. Error No.
1)

Problem
Cooling Fan (Fan1, Fan2 and/or Fan3) malfunction. NO

Possible Solution
Replace the Power C.B.A.Still NG, replace the Projection Unit. Still NG, replace the Main C.B.A. Replace the Projection Unit. Replace the Projection Unit. Only the Fan3 stops. Replace the Fan3.

Are the Fan1, Fan2 and Fan3 operating?

Only the Fan1 stops. Only the Fan2 stops.

2)

Mis-installed the Lamp Cover (the Lamp cover is open).

1. Tighten the screw of the Lamp Cover. 2. If still NG, replace the Cover SW (SW2911) on the Cover Switch C.B.A. 3. If still NG, replace the Main C.B.A. 4. If still NG, replace the Projection Unit. Remove P2303 connector on the LCD Drive C.B.A. and check if the resistance between pin1 and pin2 of P2811 on the Thermistor 1 C.B.A. is 5k 200k . If NG, replace the Temperature Sensor (R2811) on the Thermistor 1 C.B.A. Still NG, replace the Projection Unit. Still NG, replace the Main C.B.A. Note: The Projection Unit includes LCD Drive C.B.A.

3)

The temperature sensor (R2811) on the Thermistor 1 C.B.A. on the Fan 1 is short or open.

4)

It indicates when the temperature detected by the Temperature Sensor (R2811) on Thermistor 1 C.B.A. exceeds 55 °C (131 °F). 1. The surrounding temperature of the place of use may be too high. 2. The vents on the rear may be blocked.

1. Relocate the unit to a proper location. � Do not place in direct sunlight and other sources of direct heat. � Do not place the unit in humid or dusty location, or areas exposed to smokeor steam. (surrounding temperature should be between 0 °C (32 °F) and 40 °C (104 °F) and humidity should be between 20 % and 80 % (with no condensation).) � The vents are not blocked. It is recommended that a gap of at least 10 cm is left all around the unit even when it is placed inside a cabinet or between shelves. 2. Check if the fans are operating properly.

5)

1. 2. 3. 4.

The Lamp is not cooled off. 1. Confirm that the Thermal Fuse Unit (115�C(239�F)) on the Lamp House is not open. Thermal Fuse Unit (115�C (239�F)) is defective (open). 2. Wait until the Lamp is cooled off and try to turn the power back on. If same error LED The Lamp is defective (crack). indication continues, remove the Lamp and visually inspect it. If it is cracked, it must be The Lamp voltage becomes more over 130V or less replaced. If the Lamp is not cracked, replace the Ballast C.B.A. than 30V. 3. If still NG, replace the Main C.B.A. 5. The Ballast C.B.A. is defective. 6. The Main C.B.A. is defective. The Lamp is defective (short of the Lamp). Thermal fuse (F1302) 117 °C (243 °F) on the Ballast C.B.A. is open due to abnormal temperature rise. The Ballast C.B.A. is defective. +30V line on the Main C.B.A. error. Replace the Lamp. Replace the Ballast C.B.A. If the Lamp does not light up after attempting turning on the power 2 or 3 times, replace the Ballast C.B.A. 1. Replace the Power C.B.A. 2. If still NG, replace the Main C.B.A. 3. If still NG, replace the Tuner C.B.A. 1. Replace the Power C.B.A. 2. If still NG, replace the Main C.B.A. 3. If still NG, replace the Rear Jack C.B.A. 4. If still NG, replace the Projection Unit. 1. Replace the Power C.B.A. 2. If still NG, replace the Main C.B.A. 3. If still NG, replace the Rear Jack C.B.A. 4. If still NG, replace the Tuner C.B.A. 5. If still NG, replace the Projection Unit. 1. Replace the Power C.B.A. 2. If still NG, replace the Main C.B.A. 1. Replace the Power C.B.A. 2. If still NG, replace the Main C.B.A. 1. Replace the Power C.B.A. 2. If still NG, replace the Main C.B.A. Remove P2304 connector on the LCD Drive C.B.A. and check if the resistance between pin1 and pin2 of P2821 on the Thermistor 2 C.B.A. is 5k 1M . If NG, replace the Temperature Sensor (R2821) on the Thermistor 2 C.B.A. Still NG, replace the Projection Unit. Still NG, replace the Main C.B.A. Note: The Projection Unit includes LCD Drive C.B.A. 1. Relocate the unit to a proper location. � Do not place in direct sunlight and other sources of direct heat. � Do not place the unit in humid or dusty location, or areas exposed to smokeor steam. (surrounding temperature should be between 0 °C (32 °F) and 40 °C (104 °F) and humidity should be between 20 % and 80 % (with no condensation).) � The vents are not blocked. It is recommended that a gap of at least 10 cm is left all around the unit even when it is placed inside a cabinet or between shelves. 2. Check if the fans are operating properly. 1. Cleaning the Air Filter on the Projection Unit. 2. If still NG, replace the Projection Unit. 3. If still NG, replace the Main C.B.A.

6) 7) 8) 9)

10)

+9V line on the Main C.B.A. error.

11)

+5V line on the Main C.B.A. error.

12) 13) 14) 15)

+3.3V line on the Main C.B.A. error. -5V line on the Main C.B.A. error. +6V line on the Main C.B.A. error. The temperature sensor (R2821) on the Thermistor 2 C.B.A. on the Lamp House is short or open.

16)

It indicates when the temperature detected by the Temperature Sensor (R2821) on Thermistor 2 C.B.A. exceeds 85 °C (185 °F). 1. The surrounding temperature of the place of use may be too high. 2. The vents on the rear may be blocked.

17)

Clogged air filter of the Fan Case Unit.