Sony HCD-GR3 Service Manual page 12

Record Bias Adjustment (Deck B)
Procedure :
1. Mode : Record
VIDEO IN
1) 315Hz
2) 10kHz
AF OSC
600
attenuator
2. Mode : Playback
recorded
position
set
main board
CN307 Pin 1 (L-CH)
Confirm playback the signal recorded in step 1 become adjustment
level as follows.
If these levels do not adjustment level, adjustment the RV304 (L-
CH) and RV404 (R-CH) on the main board to repeat steps 1 and 2.
Adjustment level : Playback output of 10kHz level diffrence
against 315Hz reference should be ±0.5 dB.
Adjustment Location : MAIN board
Record Level Adjustment (Deck B)
Procedure :
1. Mode: Record
VIDEO IN
315Hz 51.2 mV (–23.6 dB)
AF OSC
600
attenuator
} 51.2 mV (–23.6 dB)
blank tape
CS-123
set
level meter
Pin 3 (R-CH)
blank tape
CS-123
set
2. Mode: Playback
recorded
portion
Confirm playback the signal recorded in step 1 become adjustment
level as follows.
If these levels do not adjustment level, adjustment the RV303 (L-
CH) and RV403 (R-CH) on the main board to repeat steps 1 and 2.
Adjustment level :
CN307 playback level : 47.2 to 53.0 mV (–24.3 to –23.3 dB)
Adjustment Location
[MAIN BOARD] (Component Side)
— 12 —
level meter
set
main board
CN307 Pin 1 (L-CH)
Pin 3 (R-CH)
CN307
CN308
RV401
RV304
RV404
RV303
IC303
RV403
RV
302
RV
RV301
402
RV380