Philips 26FW5220, Service Manual

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No TV but PC is present
1. Check if HSYNC and VSYNC are present at PIN 3 of 7071 and 7015.
2. If they are present, check RGB output.
3. If there is no RGB output, the IC TDA120xx can be failed.
Comb Filter not working
1. Check the option bit 5 in SAM.
2. Check NVM setting. Address 1229 is 0000.
Power Supply
Check fuses
This power supply contains three fuses. One is near the mains inlet (marked on the board as
1102) and two other are near the output connectors (marked 1610 and 1660).
1. Check with power supply in off state by means of ohmic measurement.
2. Fuse 1102 may open in case of severe lightning strikes and/or failures in the power supply.
Despite the fact, that this fuse is mounted in a fuse holder and the marking text on the
board, it is not meant to be field replaceable.
3. Fuses 1610 and 1660 may open in case a severe overload of the 12 V outputs.
Replacement of the power supply is needed, but not before the cause of the overload
conditions is resolved.
Standby mode
1. Apply a 12 ohm load resistor of sufficient power rating to all outputs (+3 V3, +12 VAL, +12
VL and +24 V). Connect the STBY pin to GND.
2. Over an input voltage range of 90 V_ac to 264 V_ac only the +3 V3 output shall be up and
within regulation (±5%). The voltage on the POWER DOWN pin shall be < 0.3 V at an input
voltage below 160 V_ac, and 3.3 V ±10% at an input voltage higher than 240 V_ac.
Normal mode:
1. Apply a 12 ohm load resistor of sufficient power rating to all outputs (+3 V3, +12 VAL, +12
VL and +24 V). Connect the STBY pin to the +3 V3 output.
2. Over an input voltage range of 90 V _ac to 264 V_ac all outputs shall be up and within
regulation (±5%). The voltage on the POWER DOWN pin shall be 3.3 V ±10% over the
entire input voltage range. Additionally, the voltage on the big capacitor mounted flat on the
PCB shall be 400 V ±10%.