Sony Betacam SX DNW-A100 Maintenance Manual page 253

2. Offset Level Adjustment
Measuring equipment: Oscilloscope
n
More than 20 minutes should elapse after turning the power on, when this adjustment is performed.
(1) Short-circuit TP101/APR-12(B-3) and E100/APR-12(C-3) with a shorting clip.
(2) Short-circuit TP201/APR-12(F-3) and E200/APR-12(G-3) with a shorting clip.
(3) Connect and set the oscilloscope as follows:
CH-1: TP700/APR-12(G-3), DC 5 V/DIV, 2 us/DIV
CH-2: TP701/APR-12(G-6), DC 5 V/DIV
Trigger: CH-2, _ slope
(4) Adjust 1RV103/APR-12(D-2) so that the audio CH1 part of the waveform at TP700 makes the same
waveform to the Figure 1 (left side).
(5) Adjust 1RV203/APR-12(G-2) so that the audio CH2 part of the waveform at TP700 makes the same
waveform to the Figure 1 (right side).
Oscillocsope
TP701
16-Bit
TP700
(OK)
Audio CH1
NG
Figure 1. Waveform of CH1/CH2 Offset Level Adjustment
(6) Disconnect the shorting clips from TP101, TP201,
E100, and E200.
DNW-A100/A50/A45
DNW-A100P/A50P/A45P
4-Bit 16-Bit 4-Bit
Audio CH2
A B C D
A No.
E500
RV504
RV502
TP501
TP500
RV500
S500
RV503
RV501
TP101
COR100
RV103
RV100
COR101
+4 –3
0 –20
20 18 16
RV101
RV102 E100
TP100
COR300
16 18 20
COR301
UNITY (L) VAR (L) UNITY (R)
COR302
+4
TP300 TP400
0
–3 >EP–GW<
–20
RV300
E300
APR-12 Board (Side A)
6-2. APR-12 Board Replacement
APR–12 E F G
LOTNO, S NO,
E600
RV605
TP601
1
RV602
TP600
RV603 RV600
S600
RV604
RV601
2
TP201
COR200
RV203
RV200
COR201
+4 –3
0 –20
E200
3
20 18 16
RV201
TP560
RV202
TP200
TP700
4
COR400
16 18 20
COR401
VAR (R)
5
COR402
+4
0
–3
–20
RV400
E400
6
TP701
7
6-15