KV-BT21N40 - Sony TV Service Manual (repair manual). Page 3

Read Sony KV-BT21N40 Service Manual online

– 3 –
KV-BT21N40/BT21N50/BT21N80
RM-W151
RM-W150
The units in this manual contain a self diagnostic function. If an error occurs, the STANDBY (1) indicator will automatically
begin to flash. A description of the self-diagnosis function is explained in the instruction manual. The number of times the
STANDBY (1) indicator flashes translates to a probable source of the problem. If an error symptom cannot be reproduced,
the remote commander can be used to review the failure occurrence data stored in memory to reveal past problems and
how often these problems occur.
1. DIAGNOSTIC TEST  INDICATORS
When an errors occurs, the STANDBY (1) indicator will flash a set number of times to indicate the possible cause of the
problem. If there is more than one error, the indicator will identify the first of the problem areas.
Result for all of the following diagnosis items are displayed on screen. No error has occured if the screen displays a “0”.
*
If a +B overcurrent is detected, stoppage of the vertical deflection is detected simultaneously. The symptom that is
diagnosed first by the micro controller is displayed on the screen.
** Refer to Screen (G2) Adjustment in this manual.
SELF DIAGNOSTIC FUNCTION
Diagnosis
Item
Description
Power does
not turn on
+B overcurrent
(OCP)*
V-Protect
IK (AKB)
Power supply
NG (+5V) for
Video Processor
No. of timer
STANDBY (1)
indicator flashes
Does not light
2 times
4 times
5 times
8 times
Self-Diagnostic
display/
Diagnosis result
2:0
or
2:1 ~ 255
4:0
or
4:1 ~ 255
5:0
or
5:1 ~ 255
8:0
or
8:1 ~ 255
Probable Cause
Location
• Power cord is not plugged
in.
• Fuse is burned out (F600)
A board.
• H OUT (Q805) is shorted.
(A board)
• IC751 is shorted. (C board)
• +13V is not supplied.
(A board)
• IC804 is faulty. (A board)
• Video OUT (IC1545) is
faulty. (A board)
• IC001 is faulty. (A board)
• Screen (G2) is improperly
adjusted.**
• IC604 faulty.
• IC602 faulty.
Detected
Symptoms
• Power does not turn on.
• No power is supplied on
TV.
• AC Power supply is faulty.
• Power does not turn on.
• Load on power line is
shorted.
• Has entered standby state
after horizontal raster.
• Vertical deflection pulse is
stopped.
• Power line is shorted or
power supply is shorted.
• No raster is generated.
• CRT Cathode current
detection reference pulse
output is small.
• No power supply to CRT
ANODE.
• No RASTER is generated.
Page of 124
Display

Click on the first or last page to see other KV-BT21N40 service manuals if exist.