DOWNLOAD Panasonic CT-34WDM60 Service Manual ↓ Size: 1.4 MB | Pages: 46 in PDF or view online for FREE

Model
CT-34WDM60
Pages
46
Size
1.4 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / HD6M
File
ct-34wdm60.pdf
Date

Panasonic CT-34WDM60 Service Manual ▷ View online

- 6 -
Switching po
w
er supply (T802)
+23 V output
+5 V output
+3.3 V output
IC3101
IC3106
IC3105
To each module
E-Board    F-Board
E-Board    F-Board
E-Board    L-Board
To L-Board
E-Board    A-Board
To each module
To each module
To each module
D3039 D3040
D3050 D3051
D3035 D3036
R6841
D6837
R6836
D6835
R6840
R6843
D6838
D6841
R6834
R6835
R6838
R6839
Q6831
Q6832
Q3017
R6831
R6832
R888
R833
R832
R887
R6833
Q879
D6833
D888
R890
Q890
D899
D890
D832
Q831
R835
R836
D831
BS +15 V output
+12 V output
+6 V output
IC3110
IC3109
+6 V output
IC881
+5 V output
IC3107
T3001
(BT +30 V output)
Switching
transformer
D3011 D3038
Audio +23 V
+15 V
+140 V
-15 V
+23 V
Switching pulse
TV 
+23 V
TV 
+208 V
TV 
+130 V
To L-Board
(heater voltage)
f
b
c
g
TV
+208 V
constant
voltage
IC891
TV
+130 V
error
detection
IC871
R831
E-Board  
    
F-Board
 
35
27
28
23
A20
Standby
microcomputer
Main
microcomputer
1
F6
25
40
41
U-Module
F-Board
Standby +5 V output
IC3111
Standby +B
a
e
d
 
L-Board
Self-check for the power supply system
(1)Block diagram of the power supply system
This unit is equipped with a protector circuit for the case when the +B line on the secondary side of the switching power supply
is short-circuited at all times.
Abnormalities are detected for seven +B lines per switching power supply.
Operation for detection of abnormalities
(1) Lines  
 ,  
  ,  
  , and 
  in the above figure
The collector of each transistor for detection of abnormalities becomes "H", and a voltage of about 2.5 V or about 5.0 V is
impressed to the microcomputer.
(2) Line 
 in the above figure
Abnormality detection for each regulator output voltage is performed by Zener diode and protection ON/OFF diode.
When the regulator output voltage rises, the withstand voltage fault voltage is applied to the Zener diode, the protection ON/
OFF diode is switched to ON by this fault detection, and a voltage of about 5.0 V is impressed to the microcomputer.
(3) Lines 
 and 
 in the above figure
The lines 
 and 
 both are the reset input voltage for the standby microcomputer, and when this input voltage is not pro-
vided as input to the standby microcomputer, the fault detection operates.
When fault detection operates, the microcomputer switches the relay of the switching power supply to OFF.
When the power has been cut off by the power supply protector (or by detection of abnormal high voltage), the "Power supply/
function standby/video reception" LED at the front of the unit flashes one to seven times at the time of power supply protector
operation (detection of abnormal high voltage) to facilitate discrimination of the fault location.
a
b
c
g
d
e
f
e
f
!"#$
- 7 -
(2)Flashing timing table
 When an abnormality has occurred for a power supply line, the protection circuit (power supply protector/detection of abnormal
high voltage) operate and cuts the power supply. At this time, the defective line can be identified by the number of flashes (red) of
the "Power supply/function standby/video reception" indication at the front of the unit by means of the fault line which has oper-
ated the protection circuit.
*Other than the above, the contents partly may differ according to the fault location.
Flashing twice: +6 V voltage drop (-> refer to the flowchart on page 9)
Flashing three times: +6 V voltage drop (-> refer to the flowchart on page 10)
Flashing four times: +130 V/+208 V voltage drop (refer to the flowchart on pages 11 and 12)
Flashing five times: +23 V voltage drop (-> refer to the flowchart on page 9)
Flashing six times:  +15 V/+23 V voltage drop (refer to the flowchart on pages 13 and 14)
Flashing
Flashing timing
Contents
Once
Twice
Three times
Four times
Five times
Six times
Seven times
Once
3 sec
No Light
Light
CRT drive +32 kV 
voltage rise (  g  )
RGB drive +208 V,
vertical drive -15 V 
voltage drop (  b  )
Vertical drive +15 V/ -15 V,
+23 V/audio +23 V 
voltage drop (  a  )
 +15 V/+ 12 V/+9 V/+5 V
/+3.3 V/BT +30 V 
voltage rise (  d  )
+3.3 V voltage drop (  f  )
+130 V overcurrent 
detection (  c  )
+5 V voltage drop (  e  )
% !"#$
- 8 -
Inspection procedure using the self-check function for the power supply system
Caution items at the time of inspection
Always pull the plug of the AC code before performing a continuity check.
When solder has been removed or a connector has been pulled, please restore the original condition after each inspection.
When the tester has been set to 
 a voltage with the opposite polarity of the voltage impressed when the tester is used as a
voltmeter is put out from the tester, and for inspection of a load short-circuit, connect the tester rod on the plus side (red) to
earth and the tester rod on the minus side (black) to the power supply line.
Generally, a value of 10 
 or less can be considered as a load short-circuit.
The main power/video reception LED does not light.
W
Load
BLACK
RED
The main power/video reception
LED does not light even when
the main power switch is set to ON.
Is the fuse F801 blown?
Perform short-circuit inspection
for the AC 120 V line
(T801, D841 to D844, C842, etc.).
Exchange the fuse F801.
Is a voltage of 10 V
supplied to pin 1 of the
connector E15?
Is a voltage of 5 V
supplied to pin 4
of IC3111?
Exchange U-Module
Unsolder pin 1
of the connector E15
and check if a voltage of
10 V is supplied to pin 1
of the connector
D15.
D841 to D844, C842
short-circuit inspection,
exchange
IC3111, C3124 short-circuit
inspection, exchange
IC3111 open inspection, C3071,
C3098 short-circuit inspection,
exchange
Yes
Yes
Yes
No
No
No
No
Yes
& !"#$
- 9 -
Main power/video reception LED flashes once
Main power/video reception LED flashes twice
Main power/video reception LED flashes five times
When the main power switch is
set to ON, the main power/video
reception LED lights in the order of
red -> green -> red
and flashes once.
Q509, Q510 short-circuit inspection,
simultaneous exchange
Q612, Q502 short-circuit and open inspection
D506, D404, Q401 short-circuit inspection
IC608, IC607, IC402 inspection
T551 inspection
Exchange
When the main power switch is
set to ON, the main power/video
reception LED lights in the order of
red -> green -> red
and flashes twice.
IC881 open inspection
Q890 short-circuit inspection
Exchange
When the main power switch is
set to ON, the main power/video
reception LED lights in the order of
red -> green -> red
and flashes five times.
Perform a 
continuity check 
between pins 1 and 2 of 
the connector E13 and earth 
and check for a 
short-circuit.
Perform a 
continuity check 
between pin 2 of IC3109 
and earth and check for 
a short-circuit.
IC3109 open inspection
IC3110 open inspection
Q3023 short-circuit inspection
D3039, D3050, D3022, D3035, D3011 
short-circuit inspection
Exchange
IC3109, C3117 short-circuit inspection
IC3110, C3069 short-circuit inspection
Exchange
IC3109, D3017 short-circuit inspection
IC3061, D3047, C3061 short-circuit inspection
J-Module and HM-Module short-circuit 
inspection Exchange
Short-circuit
Short-circuit
No short-circuit
No short-circuit
* Flashing is done six times in case of 
  a short-circuit on the rectification side.
' !"#$
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