Philips L01.1L AC, Service Manual

Service Modes, Error Codes, and Fault Finding

EN 24

L01.1L AC

5.

•

6 short blinks followed by a pause of 3 s,

•

1 long blink of 3 s to finish the sequence,

•

the sequence starts again. 

5.6

Protections

If a fault situation is detected an error code will be generated 
and if necessary the set will be put in the protection mode. 
Blinking of the red LED at a frequency of 3 Hz indicates the 
protection mode. In some error cases the microprocessor does 
not put the set in the protection mode. The error codes of the 
error buffer can be read via the service menu (SDAM), the 
blinking LED procedure or via ComPair. 
 
To get a quick diagnosis the chassis has two service modes 
implemented:
•

The Customer Service Mode (CSM).

•

The Service Default Alignment Mode (SDAM). Start-up of 
the set in a predefined way and adjustment of the set via a 
menu and with the help of test patterns.

5.7

Repair Tips

Below some failure symptoms are given, followed by a repair 
tip.
•

Set is dead and makes hiccupping sound. “MainSupply” 
is available. Hiccupping stops when de-soldering L5561, 
meaning that problem is in the “MainSupply” line. No output 
voltages at LOT, no horizontal deflection. Reason: line 
transistor 7460 is defective.

•

Set is dead, and makes no sound. Check power supply 
IC 7520. Result: voltage at pins 1, 3, 4, 5 and 6 are about 
180 V and pin 8 is 0 V. The reason why the voltage on 
these pins is so high is because the output driver (pin 6) 
has an open load. That is why MOSFET 7521 is not able to 
switch. Reason: feedback resistor 3523 is defective. 
Caution: be careful measuring on the gate of 7521; 
circuitry is very high ohmic and can easily be damaged!

•

Set is in hiccup mode and shuts down after 8 s. Blinking 
LED (set in SDM mode) indicates error 5.  As it is unlikely 
that the “POR” and “+8V protection” happen at the same 
time, measure the “+8V”. If this voltage is missing, check 
transistor 7480. 

•

Set is non-stop in hiccup mode. Set is in over current 
mode; check the secondary sensing (opto coupler 7515) 
and the “MainSupply” voltage. Signal “Stdby_con” must be 
logic low under normal operation conditions and goes to 
high (3.3 V) under standby and fault conditions.

•

Set turns on, but without picture and sound. The screen 
shows snow, but OSD and other menus are okay. Blinking 
LED procedure indicates error 11, so problem is expected 
in the tuner (pos. 1000).  Check presence of supply 
voltages. As “5V” at pin 5 and 7 are okay, 
“VT_supply” at pin 9 is missing. Conclusion: resistor 3460 
is defective.

•

Set turns on, but with a half screen at the bottom. 
Sound is okay. Blinking LED (set in SDM mode) indicates 
error 3. Check “11V” and “+50V”. If they are okay, 
problem is expected in the vertical amplifier IC 7471. 
Measure with a scope the waveform on pin 17 of the UOC. 
Measure also at pin 1 of IC 7471. If here the signal is 
missing, a defective resistor R3244 causes the problem