LG 50PQ30 Training Manual page 133

Checking the Y - Drive Upper or Lower Board Tip:
Checking the Y - Drive Upper or Lower Board Tip:
SYMPTOM:
Set shuts down at turn on.
CHECKS: (See pages 67, 70, 71 and 74 for more details).
1. V-Scan signal input to Lower Y-Drive board low ohms or low volts (Diode Mode).
2. Output from any buffer shows low ohms or low volts (Diode Mode).
FIX: Found Defective Y-Drive Upper or Lower (See the Y-Drive section for checks)
1. After determining which Y-Drive board is defective using the checks shown in the
Y-Drive section, the other board can be tested separately.
• If the Upper Y-Drive is found defective, the Lower Y-Drive board can be tested.
Remove the Upper Y-Drive. Disconnect the Connector P209. Turn on the set and
confirm that the bottom half of the picture looks normal.
• If the Lower Y-Drive is found defective, the Upper Y-Drive board can be tested.
Remove the Lower Y-Drive. Disconnect the Connector P209.
• Jump either Pin 1 or 2 of P207 (V-Scan from the Y-SUS) to pin 4 or 5 of
connector P108 on the Upper Y-Drive board.
• Turn on the set and confirm that the top half of the picture looks normal.
TIP:
133 November 2009 50PQ30 Plasma