LG OM7550 - Amp Power

3-3
ONE POINT REPAIR GUIDE
2. NO AMP POWER
If the unit doesn’t work by no ±PVDD problem, repair the set according to the following guide.
2-1. FUSE/ FET
2-1-1. Solution
Please check and replace F911, Q905~Q906 on SMPS board.
2-1-2. How to troubleshoot (Countermeasure)
1) Check if the fuse F911 is open or short-circuit.
2) Check the Drain-Source or Drain-Gate, Gate-Source Resistance of Q905~Q906 with a digital multimeter.
 If it is short condition, it’s destroyed. Replace it with a new one.
(Please replace 2 FET at the same time although several FET is OK).
2-1-3. Service hint (Any picture / Remark)
< F911 >
If F911 is not short-circuit,
replace it with a same specifi cations one.
< Q905~Q906 >
If Q905~Q906 is short-circuit,
replace it with a new one.