Service Modes, Error Codes, and Fault Finding
5.
5.
Service Modes, Error Codes, and Fault Finding
Index of this chapter:
5.1 Test Points
5.2 Service Modes
5.3 Error Codes
5.4 Fault Finding
5.1
Test Points
See chapter 6 "Block Diagrams, Testpoint Overviews, and
Waveforms".
Perform measurements under the following conditions:
•
Service Default Mode.
•
Video: colour bar signal.
•
Audio: 3 kHz left, 1 kHz right.
5.2
Service Modes
This chassis does not contain a specific Service Mode. Service
and Alignment of the TV set can be done via the Factory Mode
by the service technician, see further down in this manual.
5.3
Error Codes
Not applicable.
5.4
Fault Finding
5.4.1
Power on Failure
Check whether the power supply is working properly and
whether the values of voltages normal. If those are correct,
check line transistor and transformer are working properly or
check fore or back line for defects.
5.4.2
Horizontal Deflection Transistor Defective: No Picture, No
Sound.
To find the fault for a defect horizontal deflection transistor
please check the following items:
•
Over voltage to breakdown.
•
Over current to burn.
•
Horizontal frequency too low.
•
Horizontal drive inefficient.
5.4.3
Picture Interference
•
Check if the signal line contact is good.
•
Change Tuner if is necessary.
5.4.4
Can't find any TV program
Checking method: Check the closed circuit from tuner to
picture decoder IC to detect whether there are defective
components. Or check whether the resistance of R117, R118,
R203 and R204 has increased which also could cause the
problem.
5.4.5
No Good Picture or Double Image
Check the correctness of the signal from IF1/IF2 to Q101 and
relevant circuit. In this case the problem can be Q101 and/or
SAW101.
5.4.6
Picture not or incorrect Coloured
•
Check the circuit from IC201 to R.G.B. three gun circuit.
•
Check the IC soldering and relevant circuitry on physical
damage or check for defective capacitors.
5.4.7
Picture with Horizontal Bright Line and Sound
Check both supply voltages of vertical IC301 and relevant
circuitry on correctness. Also check the vertical synchronizing
signal from IC201.
5.4.8
Remote Control Malfunction
Check the voltage on pin 64 of IC201. The normal value should
be 5.15 V. If this is correct check front control panels soldering
connections. If can't be solved, check the remote control,
crystal or transmitting diode of the remote control are in good
condition.
5.4.9
No Sound
Check power supply of sound IC (IC402) and relevant circuitry
(not exclude IC402 to be defective) or change speakers.
5.4.10 Poor Sound Quality
Check the sound system after searching the channel which
should set at DK, I or AUTO. If still has problem, check
accompany board circuit on chassis good or not.
