94
20. RA-5A Chassis Protection Block
Testing - If the Standby light blinks seven times, the problem is most likely on the D board where the Horizontal
Regulator and Horizontal Output stages are. Use this three-step method to determine if the problem is on the G,
D or A board:
1. On the D board CN8013/pin 9, verify there is 135V coming into the D board from the G board.
2. On the D board, look for 5Vp-p H drive pulses into the D board at CN8006/pin 10 from the A board.
3. On the D board, look for 5Vp-p H pulses output from the D board at CN8006/pin 6 into the A board.
Not Present - The problem is on the D board, suspect the Horizontal Output (Q5030), PWM (Q5003/Q5011)
transistors on the D board and video output ICs (C board).
Present - The D board is OK and the problem is in the sensing circuit on the A board. Suspect components
D3011, C3090, R3140 and Q3037.
FIGURE 20-11 - PROTECTION 7X INDICATION - RA-5 CHASSIS
IC8005
Q8027
T8003
HOT
Q8030-BUFF.
Q8023-DRIV
T8002-DRIV
IC3021
REG.
IC3006
VIDEO
PROCESSOR
CXA2150
IC3005
REG.
55 61
19 21
26
25
34
40
IC001
MAIN
MICRO
M306V2ME
A20
50
28
31
67
5
10
6
PROT.LATCH
Q6105,Q6118 (G BD.)
11V (G BD.)
R3137
D3009
STBY LED
(HB BD.)
Q522
9V
SOURCE
CN6103/
CN3016
CN013/
CN3022
R3139
D3012
S DATA
H DRIVE
Q3037
R3140
C3090
Q3062
R3288
C3186
100
+
D3026
R3287
P
+15V
N
P
D3011
R3144
12V
R8189
Q8031
Q8101
D8027
YOKE
Q8024
H OUT
D8021
DAMP
C8096
C8097
C8098
R8174
+135V
(G BD.)
D8026
5.6V
CN3007/
CN8006
PROTECT
MUTE
N
SCLK
A23
B19
B BD.
D BD.
A BD.
9/4/01
29TVP12 1347
5V p-p
0.6VDC
HORIZ. PULSE
DETECT. CIRCUIT
Содержание KD-34XBR2 - 34" Hdtv Fd Trinitron Wega
Страница 77: ...74 RA 5A Chassis Board Layout ...
Страница 108: ...APPENDIX ...