Philips LC4.1E Service Manual page 16

EN 16 5. LC4.1E AB
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.
5.7.4 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 PWB shall
be 400 V ±10%
Service Modes, Error Codes, and Fault Finding