Panasonic rear projection TV TC-51P800G boot immediately protect the fault repair example - appliance repair - Huaqiang electronic network

LC03-3.3 SOP8 TVS Static Protection 3.3V

A Panasonic rear projection TV model TC-51P800G experienced an issue where it would power on and immediately trigger a protection mode. After removing the cluster line, the protection was no longer active, indicating that the problem was in the aggregation loop. Further inspection revealed that three sockets were damaged— one was burnt, and the other two were slightly damp. Replacing all three sockets resolved the immediate issue, but the TV still wouldn’t turn on. Upon testing, the acceleration voltage was only 80V (normally over 200V). When touching the focus, it felt hot, and the acceleration voltage fluctuated between 150V and 200V. The high-voltage package also became very hot. When turned on, the screen displayed a bright red retrace line. After removing the red tube’s tail plate, the cathode voltage was measured at only 70V, which was significantly low. However, the acceleration voltage was normal at 200V. The tail plate was found to be very wet, indicating coolant leakage from the projection tube. The area was cleaned with banana water and dried using a hot air blower. Once this was done, the TV turned on with normal brightness. To fully resolve the issue, the coolant leakage from the projection tubes needed to be addressed. All three tubes were removed, and it was discovered that the coolant inside each was highly pressurized and bulging. The sealant caps were intact, suggesting that the pressure was too high, leading to the leak. The sealant cover was removed, and the excess coolant was carefully absorbed with toilet paper before reinstalling the components. After adjusting the power settings and realigning the convergence, the TV functioned properly, and the repair was considered successful.