Electronic Viewfinder (E. Vf) Adjustment; Black Level; Gain - JVC GR-DVF11U Service Manual

3.4

ELECTRONIC VIEWFINDER (E. VF) ADJUSTMENT

Notes: Unless otherwise specified, all measurement points
and adjustment parts are located on E. VF board.
1
1 0 B/W VF PWB
YB20861-01-01
12
Fig. 3-4-1 E. VF board (A)
Q7001
VR7002
BLACK LEVEL
1 0 B/W VF PWB
YB20861-01-01
Fig. 3-4-2 E. VF board (B)

3.4.1 Black level

Subject
Mode
Equipment
Measurement point
Adjustment part
Specification
1) Observe waveform at pin 4 of the CN7002.
2) Adjust VR7002 so that DC level of "A" (between the
pedestal level and GND, see Fig. 3-4-3) of a waveform
becomes 2.5 ± 0.05 V DC.
CN7003
48 37
2 1
36
10
9
IC7001
25
2
1
ZP7008
13 24
19 1
CN7001
CN7002
20 2
VR7001

GAIN

• Camera picture
• Gray scale
• EE
• Oscilloscope
• CN7002 pin 4 (VIDLO)
• VR7002 (Black level)
• "A"=2.5 ± 0.05 VDC
"A" = 2.5±0.05VDC
GND(0V)
Fig. 3-4-3 Black level
3.4.2 Gain
Subject
Mode
Equipment
Measurement point
Adjustment part
Specification
1) Observe waveform at pin 4 of the CN7002.
2) Adjust VR7001 so that level of "A" (see Fig. 3-4-4) of a
waveform becomes 2.7 ± 0.05 Vp-p.
"A" = 2.7±0.05VP-P
"A"
Fig. 3-4-4 Gain
"A"
H.rate
• Camera picture
• Gray scale
• EE
• Oscilloscope
• CN7002 pin 4 (VIDLO)
• VR7001 (Gain)
• "A"=2.7 ± 0.05 Vp-p
H.rate
3-3