Panasonic TC-PXXGT30, Technical Manual

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8 Blinks Error Code
The SOS Detect circuit in the Sustain board monitors:
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Physical connection between the panel and the SS board.
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The output of the sustain drive circuit.
Under normal condition, Q16280 is on. When Q16280 is on, a low is provided to the anode of D16255.
If any abnormality occurs on the sustain drive circuit or one of the FPC cables (SS53, SS54 or SS56)
opens, Q16255 turns off and a high is provided to the anode of D16255 (D255).
This high is provided to pin 10 of IC5000 on the A board. When this happens, the TV shuts down and the
power LED blinks 8 times.
To determine if the 8 blinks is caused by the A board, SS board, or the Panel:
• Isolate the SS board and check if the TV stays on when it’s turned on.
• If the TV does not stay on after disconnecting the SS board, the A board is defective.
• If the TV stays on, then the SS or the Panel is defective.
• Check continuity between pins 1 and 2 of connectors SS53, SS54 and SS56. If open, the panel might
be defective. (Check for loose connection between the flex-cables and the SS board).
• If continuity is OK, the SS board is defective.
1. Abnormality of the Sustain drive circuit.
2. Open or loose connection between the SS board and FPCs from the panel.
3. When SS53, SS54 or SS56 are disconnected.
4. When SC20 is disconnected.
5. Wrong diagnostic by the A board
These 5 conditions can cause the TV to shut down and the power LED to blink 8 times
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