Fault Finding and Repair Tips
GB 7
A10PTV2.0 NTSC
5.
5. Fault Finding and Repair Tips
The lowing topics are covered:
•
Test points
•
Service Modes
•
Error code buffer and error codes
•
The “blinking LED” procedure
•
Trouble shooting tips
•
Customer Service Mode
5.1
Test Points
The A10 PTV chassis is equipped with test points shown on
the schematic diagrams.
Each test point has a reference number indicating the
schematic diagram on which it is located.
•
A F106, A I126, etc.: Test points for the Large Signal
Panel [A1 - A3]
•
C F001, C I001, etc.: Test points for the Small Signal
Panel [C1 - C11]
•
G F114, G I001, etc.: Test points for the PFC Filter Panel
[G]
•
J F004, J F006, etc: Testpoints for the SVM Panel [J]
•
K I001, K I002: Test points for the Center Channel Switch
[K]
•
M I004, M I005: Test points for the Local Control [M]
Measurements should be performed under the following
conditions:
Video: color bar signal
Audio: 3kHz left, 1kHz right
Note:The measurements at the following test points were
taken using a 100:1 probe:
•
A I142
•
A I220
5.2
Service Default Mode (SDM)
5.2.1
Introduction
The Service Default Mode (SDM) is a technical aid for the
service technician. The Service Default Mode (SDM)
establishes fixed, repeatable settings of customer controls,
which allow consistent measurements to be made. The SDM
also initiates the blinking LED procedure and, if necessary,
overrides the 5V protection. This mode also allows the
operating hours, the software version and error codes to be
read.
The SDM Places the Set in the Following Pre-defined
Conditions:
•
Tuning frequency set to channel 3.
•
Volume level set to 25% (of the maximum volume level).
•
Other picture and sound settings set to 50% (mid-range).
The Following Functions are Turned Off in SDM (and
After Leaving SDM):
•
Timer
•
Sleep timer
The Following Functions are Disabled During SDM (and
Enabled After Leaving SDM):
•
Parental lock
All other controls operate normally.
5.2.2
Entering Service Default Mode
To enter the Service Default Mode, press the following key
sequence on the remote control transmitter:
0-6-2-5-9-6-MENU
Do not allow the display to time out between entries while
keying the sequence.
Upon entry into the Service Default Mode, the letters “SDM”
will be displayed at the upper right corner of the screen.
Figure 5-1
5.2.3
Special SDM Functions
Access to Normal User Menu
Pressing the “MENU” button on the remote control switches
between the SDM and the normal user menus (with the SDM
mode still active in the background)
Run Timer, Software Identification, and Error Buffer
Press the Index or status button on the remote control to
toggle the OSD (except “SDM”) ON and OFF to prevent the
OSD from interfering with measurements and oscilloscope
waveforms.
Access to SAM
To access the Service Alignment Mode while in the SDM
press the “” and “VOLUME -“ buttons on the local
keyboard simultaneously for at least 4 seconds.
5.2.4
Exiting Service Default Mode
To exit the Service Default Mode, press the Power button.
Red CRT
Side Jack
Panel
LSB Panel
Center
Channel
Switch
Filter Panel
Green CRT
Blue CRT
PIP Panel
SSM Panel
AC Power
Switch Panel
SSB Module
Keyboard &
IR LED Panel
SVM Panel
CL 16532050_001.eps
090501
