Sony TVP-08, Training Manual

Page: 11 / 139

3
Self-Diagnostics
Overview
The RA-4 chassis employs a Self-Diagnostic system that uses the Timer
LED and an on screen menu to help indicate where the problem with the
set has occurred. You will generally have to use the flashing LEDs since
the set will be shut down. AC power must be disconnected in order to turn
the set off once shutdown has occurred.
When a failure occurs, all of the circuits covered by the Self-Diagnostics,
except AKB, send a signal to the OSD CPU. The OSD CPU sends data
to the Main CPU that indicates how many times the Timer LED will flash.
The AKB circuit located in the Video Processor IC sends data over the
I2C bus directly to the Main CPU. In addition, each circuit, except AKB
and High Voltage, send a signal to the latch circuit to shut the set down
when failure occurs.
•EXAMPLE
<Diagnosis Items>
• +B overcurrent
• +B overvoltage
• Vertical deflection stop
< FRONT PANEL >
TIMER/STANDBY indicator
The number of times the LED blinks may correspond to that shown in the
following table:
Diagnosis item Standby/ Self-diagnosis
sleep lamp, screen displa y,
Number of blinks Diagnosis item: Results
• Power not ON Not lit
+B OCP detection LED blinks 2 times 2 : +B OCP XX
+B OVP detection LED blinks 3 times 3 : +B OVP XX
V detection LED blinks 4 times 4 : V STOP XX
AKB detection LED blinks 5 times 5 : AKB XX
H detection LED blinks 6 times 6 : H STOP XX
HV abnormality detection LED blinks 7 times 7 : HV XX
Audio abnormality detection LED blinks 8 times 8 : AUDIO XX
*
: XX the range of values for number of operations is 00-99. For 99 or higher there is no count up
and the number remains at 99.
<Number of Blinks>
2 times
3 times
4 times
Lamp OFF :
3.0 seconds
Lamp ON : 0.3 seconds
Lamp OFF : 0.3 seconds
If the problem is intermittent and you can get the set to operate, you can
display a menu showing the number of times failures have occurred. This
is done by pressing the following sequence of buttons on the remote.
Display Channel 5 Vol - Enter
The display will look as follows.
SELF CHECK
2 : +B OCP XX
2 : +B OCP XX
3 : +B OVP XX
4 : V STOP XX
5 : AKB XX
6 : H STOP XX
7 : HV XX
8 : AUDIO XX
9 : WDT XX
XX the range of values for number of
operations is 00-99.
For 99 or higher there is no count up
and the numberremainsat 99.
Diagnosis
Results