Philips 26FW5220, Service Manual

Page: 36 / 150

Tuner and IF
No Picture in RF mode
1. Check if 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 defected. 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.
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 1005 and 1601, 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 3-IC7016 (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 failed.
Note:
l
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.
l
If the H-out (pin 67) has a signal (or has a signal for a very short time), change IC7016
(NE555).