Service Modes, Error Codes, and Fault Finding
EN 17LC4.41E AA 5.
5.7.3 Flash New Scaler Software
When you need to flash new scaler software, follow the
instructions in ComPair. Make sure you put the set in one of the
Service Modes, SDM/SAM/CSM, before you start flashing.
This reduces the risk of the set hanging during the flashing
procedure.
5.7.4 Tuner and IF
No Picture in RF Mode, but there is a Noise Raster
1. Check whether picture is present in AV. If not, go to Video
processing troubleshooting section.
2. If present, check if the Option settings are correct.
3. Check if all the supply voltages are present (3.3/5/8/12/33
V).
4. Check if the I
2
C lines are working correctly (3.3 V).
5. Manually store a known channel and check if there is IF
output at Tuner pin 11.
6. Check the tuning DC voltage at pin 2 of the Tuner. The DC
voltage should vary according to the frequency/channel
being chosen.
7. If the tuning voltage is OK, check the tuner output, pin 11.
8. If it has no output, the Tuner may have a defect. Change
the Tuner.
Sound in Picture Problem for L' System (rolling horizontal
lines)
1. Check whether AGC L' in SAM mode is set to 0.
2. If yes, align the set to correct value.
Required System is not Selected Correctly
Check whether a Service jumper (#4204 & 4205, 0805 size) is
present. If yes, remove it.
5.7.5 Video Processing
No Power
1. Check +12 V and 3V3 at position 1J02.
2. If no supply, first check the connector 1J02.
3. If the connector is correct, check the power supply board.
Power Supply is Correct, but no Green LED
1. Check if the connectors 1K00 are properly inserted.
2. If they are inserted correctly, check if the 3V3 is present.
No Picture Display (blank screen with correct sound
output)
1. Check whether the user menu is visible.
2. If the user menu is OK, activate teletext mode.
3. If teletext is OK, the problem is in the ADC (B18) &
Columbus 3D combfilter (B19), if present (depending on
model, see also paragraph “Teletext Path” in chapter 9).
Note: For fault finding purposes, it is important to know the
following: in Pixel Plus and Digital Crystal Clear models, which
have an ADC (B18) and Columbus 3D combfilter (B19), the
digital input of the scaler is used for the digital video path
(Hercules output), whereas the analogue RGB input (analogue
input of the 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 (blank
screen), the digital path (Hercules - ADC - Columbus - Scaler)
is faulty. If there is sound but no teletext, the back-end part
(Scaler - PDP panel) is faulty. In Crystal Clear models, which
do not have an ADC and Columbus, the RGB path (analogue
input of scaler) is used for both video and teletext.
No TV, but PC is Present
1. Check if Hsync_SDTV and Vsync_SDTV are present at pin
1 & pin13 of 7E03.
2. If they are present, check teletext output.
3. If there is no teletext output, the IC TDA150xx may be
defect.
5.7.6 Power Supply
Check Fuse
The power supply (various models are used) contains one fuse
near the AC input connector X002.
1. Check with power supply in “off” state by means of ohmic
measurement.
2. Fuse X102 may open in case of severe lightning strikes
and/or failures in the power supply.
3. Check the standby signal at pin 10 of X200. ON is HIGH,
OFF is LOW. During standby mode only the 3V3 is present
at pin 10.
Protections Concept on Power Supply Board (two models)
1. 12 V output (pin 8 of X200): Short-circuit protected by 2.5
A fuse X610. Over-voltage protection when output voltage
is more than 40% above nominal value.
2. Vaudio output (+18 or +24 V, depending on power
supply model used); (pin 1 of X200): Short-circuit proof
(+18 V version has 2.5 A fuse X660). Over voltage
protection when output voltage is more than 40% above
nominal value.
3. 3V3STBY 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.
4. 24 V output (for inverter X520 & X530): Short-circuit
proof with auto-restart. Over voltage protection when
output voltage is more than 40% above nominal value.
Standby Mode
1. Apply a 12 ohm load resistor of sufficient power rating to all
outputs mentioned above (+12 V, +18/ 24 V, +3V3 and +24
V). Connect the STBY pin (pin 10 of X200) to logical “L”
(low), i.e. to GND.
2. Over an input voltage range of 90 V
AC
to 276 V
AC
only the
+3V3 STBY output shall be up.
Normal Mode:
1. Apply a 12 ohm load resistor of sufficient power rating to all
outputs mentioned above (+12 V, +18/ 24 V, +3V3 and +24
V). Connect the STBY pin (pin 10 of X200) to logical “H”
(high), i.e. to the +3V3 STBY output via a 2,2 k pull up
resistor.
2. Over an input voltage range of 90 V
AC
to 276 V
AC
all
outputs shall be up. The voltage on the +3V3 STBY output
shall be 3.3 V over the entire input voltage range. The
voltage on the big 400 V capacitor on the power supply
should also be 400 V ± 10%.
To Next Page
Loading...
Need help?
General
