PHILIPS - 32PF 5320/28 (Service Mode, Error Codes & Fault Finding] Cont:-
Philips 32PF 5320 Service Mode, Error Codes & Fault Finding [Cont:]
NO PICTURE, BLANK SCREEN WITH CORRECT SOUND OUTPUT.
- Check whether the user menu is visible.
- If the user menu is OK, activate teletext mode.
- If teletext is OK, the problem is in the ADC [B18]&[Columbus 3D combfilter [B19], if present [depending on model].
- If the user menu is not visible, check the LCD panel back light is ON.
- If the back light is OFF, the problem is in the power supply
board or LCD panel. Also check pin 12 (Lamp_ON_OFF) of 1J02. It should
be high, during normal operation.
Fault finding purposes, it is important know the following:-
In Pixels Plus and Digital Crystal Clear models, which have an ADC
[Analogue to Digital Converter] (B18), and Columbus 3D comb filter
(B19), the digital input of the scaler is used for digital video path
(Hercules output), whereas the analogue RGB output , analogue input of
scaler, is only used for teletext. This means that, no mixed mode
[video plus teletext simultaneously] is possible. If there is sound and
teletext, but no video and user menu, the digital path
[Hercules-ADC-Columbus-scaler] is faulty. If there is sound, but no
teletext, the back end part (Scaler-LCD panel] is faulty. In crystal
clear models, which do not have and ADC and Columbus, the RGB path
(analogue input of scaler) is used for both video and teletext.
NO TV _ PC IS PRESENT
- Check the Hsync_SDTV and Vsync_SDTV are present at pin 1 & pin 13 of 7E03.
- If they are present, check teletext output.
- If there is no teletext output, the IC TDA 150XX may be the defect.
POWER SUPPLY
Check Fuse. The power supply contain one fuse near the AC input connector X002.
- Check the power supply in OFF state by means of ohmic measurement.
- Fuse may open in case of severe lightning strikes and/or failures in the power supply.
- Check the Standby signal at pin 10 of X200. On is High, Off is Low. During standby mode, only 3.3V is present at pin 10.
PRECAUTIONS ON POWER SUPPLY BOARD.
- 12V Output (Pin 8 of X200): Short circuit protected by 2.5 Amps
fuse X610. Over voltage protection when output voltage is more than 40%
above nominal value. - V audio output(+18V or +24V, depending power supply model used);
(Pin 1 of X200): Short-circuit proof(+18 V version has 2.5 Amps fuse
X660). Over voltage protection when output voltage is more than 40%
above nominal value. - 3V3 Standby output (pin 3&4 of X200): Short circuit proof
with auto restart. Over voltage protection when output voltage is more
than 40% above nominal value. - 24V output (for inverter X520 & X530); Short-circuit proof,
auto restart. Over voltage protection when output voltage is more than
40% above nominal value.
STANDBY MODE
- Apply a 12 Ohm load resistor of sufficient power rating to all
outputs mentioned above [+12V,+18/24V, +3.3V and +24V]. Connect standby
pin (pin 10 of X200) to Logical "L" (Low), ie to ground. - Over an input voltage range of 90VAC to 276VAC, only the +3.3V standby output shall be up.
NORMAL MODE
- Apply a 12 Ohm load resistor of sufficient power rating to all
output mentioned as above. Connect the standby pin to Logical High, ie,
to 3.3V via a 2.3kohms pull up resistor. - Over an input voltage range of 90VAC to 276VAC, all outputs shall
be up. The voltage on the +3V3 standby output shall be 3.3V over the
entire input voltage range. The voltage on the big 400V capacitor on
the power supply should also be 400V +/-10%.
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