DOWNLOAD Sony HCD-GZR77D / MHC-GZR77D Service Manual ↓ Size: 4.64 MB | Pages: 98 in PDF or view online for FREE

Checking Location: DMB19 board (Side A)

When the optical pick-up assy is replaced, perform the “Execute 
IOP Measurement”.
 

Execute IOP Measurement (See page 22)

[TEST DISC LIST]
Be sure to use the DVD disc that matches the signal standards of 
your region.
• CD
 

  YEDS-18  (Part No.: 3-702-101-01)

 

  PATD-012  (Part No.: 4-225-203-01)

• DVD SL (Single Layer)
    NTSC :  HLX-503 

(Part No.: J-6090-069-A)

 

  HLX-504 

(Part No.: J-6090-088-A)

    PAL  :  HLX-506 

(Part No.: J-6090-077-A)

• DVD DL (Dual Layer)
    NTSC :  HLX-501 

(Part No.: J-6090-071-A)

 

  HLX-505 

(Part No.: J-6090-089-A)

    PAL  :  HLX-507 

(Part No.: J-6090-078-A)

Procedure:
1.  Connect an oscilloscope to CN105 pin 6 (RFMON) and 

CN105 pin 3 (GND) on the DMB19 board.

2.  Turn the power on.
3.  Set the test disc (refer to the TEST DISC LIST) on the tray 

and press [Y] button to playback.

4. Confi rm that oscilloscope waveform is clear and check 

RFMON signal level is correct or not.

Note:   A clear RFMON signal waveform means that the shape 

“◊” can be clearly distinguished at the center of the 
waveform.

Procedure:
1.  Turn on the set.
2.  Input the following signal from signal generator to FM 

antenna input directly.

Carrier frequency: A = 87.5 MHz, B = 98 MHz, C = 108 MHz

Deviation 

: 75 kHz

Modulation  : 1 kHz
ANT input  : 35 dB

μ (EMF)

Note:   Use 75 ohm coaxial cable to connect signal generator and 

the set.

 

You cannot use video cable for checking.

 

Use signal generator whose output impedance is 75 ohm.

3.  Set to FM tuner function and tune A, B and C signals.
4. Confi rm “TUNED” is lit on the display for A, B and C 

signals.

When the selected station signal is received in good condition, 
“TUNED” is displayed.

+
–

CN105 pin 6 (RFMON)

CN105 pin 3 (GND)

CN105 pin 3
(GND)

CN105 pin 6
(RFMON)

Video Level Check (VIDEO BOARD)
Purpose
This adjustment is made to satisfy the NTSC standard, and if not 
adjusted correctly, the brightness will be too large or small.

Procedure:
1.  Connect oscilloscope to VIDEO OUT jack.
2.  Load a DVD reference disc playback.
3.  Check the video signal level is 1.00±0.07Vp-p.

1.  Demagnetize the record/playback head with a head
 demagnetizer. 
2.  Do not use a magnetized screwdriver for the adjustments.
3.  After the adjustments, apply suitable locking compound to 

the parts adjust.

4.  The adjustments should be performed with the rated power 

supply voltage unless otherwise noted.

5.  The adjustments should be performed in the order given in 

this service manual.  (As a general rule, playback circuit 
adjustment should be completed before performing recording 
circuit adjustment.)

6.  The adjustments should be performed for both L-CH and 
 R-CH.
7.  Switches and controls should be set as follows unless 

otherwise specifi ed. 

• Test Tape

P-4-A063

6.3 kHz, –10 dB

Azimuth Adjustment

Note: Perform this adjustments for both decks 
Procedure:
1.  Mode:  Playback

2.  Turn the adjustment screw and check output peaks. If the 

peaks do not match for L-CH and R-CH, turn the adjustment 
screw  
so that outputs match within 1dB of peak.

0 dB = 0.775V

+
–

MAIN board
IC101
pin wh (L-CH)
pin ql (R-CH)

MAIN board
IC101
pin t; (GND)

3.  Mode:  Playback

4.  After the adjustments, apply suitable locking compound to 

the pats adjusted.

Adjustment Location:  Record/Playback/Erase Head (Deck B)

pin wh

pin t;

pin ql