Philips LC4.1E Service Manual page 15

5.5.2 How to Clear the Error Buffer
The error code buffer is cleared in the following cases:
• By using the CLEAR command in the SAM menu:
– To enter SAM, press the following key sequence on the
remote control transmitter: "062596" directly followed
by the OSD/STATUS button (do not allow the display
to time out between entries while keying the
sequence).
– Make sure the menu item CLEAR is highlighted. Use
the MENU UP/DOWN buttons, if necessary.
– Press the MENU RIGHT button to clear the error
buffer. The text on the right side of the "CLEAR" line will
change from "CLEAR?" to "CLEARED"
• If the contents of the error buffer have not changed for 50
hours, the error buffer resets automatically.
Note: If you exit SAM by disconnecting the mains from the
television set, the error buffer is not reset.
5.5.3 Error Codes
In case of non-intermittent faults, write down the errors present
in the error buffer and clear the error buffer before you begin
the repair. This ensures that old error codes are no longer
present.
If possible, check the entire contents of the error buffer. In
some situations, an error code is only the result of another error
and not the actual cause of the problem (for example, a fault in
the protection detection circuitry can also lead to a protection).
Table 5-1 Error code overview
Error Device Error description
0 Not applicable No Error
1 Not applicable -
2 Not applicable -
3 Not applicable -
4 GM5221 I2C error while communicating
with the Genesis Scaler
and/or Flash-ROM is faulty/
empty
5 Not applicable +5v protection
6 I2C bus General I2C error
7 Not applicable -
8 M24C32 I2C error while communicating
with the Scaler EEPROM
9 M24C16 I2C error while communicating
with the EEPROM
10 Tuner I2C error while communicating
with the PLL tuner
11 Not applicable -
12 Not applicable -
13 Not applicable -
5.6 The Blinking LED Procedure
Using this procedure, you can make the contents of the error
buffer visible via the front LED. This is especially useful when
there is no picture.
When the SDM is entered, the front LED will blink the contents
of the error-buffer:
• The Led blinks with as many pulses as the error code
number, followed by a time period of 1.5 seconds, in which
the Led is off.
• Then this sequence starts is repeated.
Any RC5 command terminates this sequence.
Example of error buffer: 12 9 6 0 0
After entering SDM, the following occurs:
• 1 long blink of 5 seconds to start the sequence,
• 12 short blinks followed by a pause of 1.5 seconds,
Service Modes, Error Codes, and Fault Finding
Check item Diagram
- -
- -
- -
7401 A6
7403
7930 A6
7011, 3083, A2
3084
- -
7402 A7
7099 A2
1302, 3302, A1
3303, 3327
- -
- -
- -
LC4.1E AB
• 9 short blinks followed by a pause of 1.5 seconds,
• 6 short blinks followed by a pause of 1.5 seconds,
• 1 long blink of 1.5 seconds to finish the sequence,
• The sequence starts again at 12 short blinks.
5.7 Fault Finding and Repair Tips
Notes:
• It is assumed that the components are mounted correctly
with correct values and no bad solder joints.
• Before any fault finding actions, check if the correct options
are set.
5.7.1 NVM Editor
In some cases, it can be handy if one directly can change the
NVM contents. This can be done with the "NVM Editor" in SAM
mode.
5.7.2 Tuner and IF
No Picture in RF Mode
1. Check whether picture is present in AV. If not, go to Video
processing troubleshooting section.
2. If present, check that the Option settings are correct.
3. Check that all supply voltages are present.
4. Check if I2C lines are working correctly (3.3V).
5. Manually store a known channel and check if there is IF
output at Tuner pin 11.
6. Feed in 105 dBuV at Tuner pin 11 and check whether there
is RGB output from Video Processing IC. If yes, Tuner may
be defect. Change 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
1. Check whether the Service jumper (#4022, 08 05 size) is
present. If yes, remove it.
2. Check whether SEL_IF pin is according to what is
specified.
5.7.3 Video Processing
No Power
1. Check +12 V and 3V3 at position 1910.
2. If no supply, check the connector 1910.
3. If it is correct, check the power supply board.
Power Supply is Correct But no Green Light
1. Check the two connectors 1007 and 1008, if they are
properly inserted.
2. If they are inserted correctly, check if the 3V3 is present.
No Picture Display
1. Check the RGB signal.
2. If it is present, check pin 3 of IC7006 (NE555).
3. If it has output, the problem is in SCALER part.
4. Otherwise, check H-out on pin 2 of NE555. If the input
signal of pin2 is present, but no output, the IC is defect.
Note:
• If the H-out (pin 67) doesn't have signal or the level is low,
check the output of NE555 (pin 3) during start up.
• If the H-out (pin 67) has a signal (or has a signal for a very
short time), change IC7006 (NE555).
No TV but PC is Present
1. Check if HSYNC and VSYNC are present at PIN 3 of 7007
and 7005.
5. EN 15