Sony DVCAM DSR-25, Service Manual

Page: 151 / 238

5-26
DSR-25
4-5. ELECTRIC TENSION REGULATOR CHECK AND ADJUSTMENT OF TG2/7 ARM
1. Preparation before check
1) Check that the cassette compartment block has already been
removed. (Refer to page 5-5.)
2) Set the mechanism deck to the loading end position (TG2 to 7
already moved to the loading end position and the pinch roller
is in the unloading position). Alternatively, set the mechanism
deck to the “LE position” using the mode selector II (J-9). (Refer
to page 5-5.)
3) Attach the cassette reference plate (J-11) and TG2/7 preset plate
(J-13). (Refer to page 5-25.)
4) Connect the relay board for tension regulator adjustment (J-
14) and other equipment as shown in the figure below.
2. Check and adjustment
Connect the positive (+) probe of a digital voltmeter to E.T out
(TG2: for measurement of TG2 data) or to E.T out (TG7: for mea-
surement of TG7 data). First, press the guide to the TG2/7 preset
plate (J-13), then release your hand from the guide and read the
voltmeter value. Adjust RV4 (TG2 side) or RV2 (TG7 side) until
the voltmeter measurement is 2.5
±
0.1 V (TG2 side) or 2.2
±
0.1
V (TG7 side) when releasing your hand. Then press the guide to
the TG2/7 preset plate (J-13). Adjust RV3 (TG2 side) or RV1 (TG7
side) until the voltmeter measurement is 1.3
± 0.1 V.
Attach the boss while
aligning it with the hole
of the cassette reference
plate (J-11).
Boss
TG2/7 preset plate
(J-13)
Regulated power supply
Apply +6.5 to 8.5V.
Digital voltmeter
Change the connection of the
positive (+) probe to
E.T out (TG7) and E.T out (TG2)
for measurement.
Cassette reference plate
(J-11)
CN2
Relay board for tension regulator adjustment (J-14)
16 pin
Board for tension regulator
adjustment (J-17)
E. T out (TG 2)
9 pin
DC IN (+)
DC IN (–)
E. T out (TG 7)
GND
RV1
RV3
RV2
RV4
[2.5V adjustment of TG2]
Release your hand from the
guide and rotate RV4. [2.2V adjustment of TG7]
Release your hand from the
guide and rotate RV2.
[1.3V adjustment of TG2]
Rotate RV3 while pushing
the guide. [1.3V adjustment of TG7]
Rotate RV1 while pushing
the guide.
MD-76 board
Adjustment start
1
TG2: 2.5V adjustment (MD-76 board: RV4)
Adjustment end
Good
0
TG7: 1.3V check Not good
Good
8
TG7: 2.2V check Not good
Good
5
TG2: 1.3V check Not good
Good 3 TG2: 2.5V check Not good
2
TG2: 1.3V adjustment (MD-76 board: RV3)
4
TG2: 2.5V adjustment (MD-76 board: RV4)
6
TG7: 2.2V adjustment (MD-76 board: RV2)
7
TG7: 1.3V adjustment (MD-76 board: RV1)
9
TG7: 2.2V adjustment (MD-76 board: RV2)
[Adjustment order]