System Control System Adjustments; Battery Down Adjustment (Fc-86 Board); Alignment Check (Fdd Unit) - Sony MVC-FD75 Service Manual

1-5.

SYSTEM CONTROL SYSTEM ADJUSTMENTS

1. Battery Down Adjustment (FC-86 Board)

Set the battery end voltage.
If the voltage is incorrect, the life of battery will shorten.
The image at the battery end will also be rough.
Mode
Subject
Measurement Point
Measuring Instrument
Adjustment Page
Adjustment Address
Connection:
1) Connect the regulated power supply and the digital voltmeter
to the battery terminal as shown in Fig. 5-1-20.
Preparations before adjustment:
1) Adjust the output voltage of the regulated power supply so
that the digital voltmeter display is 6.1 ± 0.1 Vdc.
2) Turn on the HOLD switch of the adjusting remote commander.
3) Turn on the power supply.
4) Set the CAMERA mode.
Adjusting method:
Order Page Address Data
1 0 01 01
2
3 3 0D
4 F 18 Dref Press PAUSE button.
5
6
7
Regulated power supply
5.80 ± 0.01 Vdc
CAMERA
Arbitrary
Displayed data of page: 3,
address: 0D
Adjusting remote commamder
F
18 to 1C
Procedure
Decrease the output voltage
of the regulated power supply
so that digital voltmeter
display is 5.80 ± 0.01 Vdc.
Read the data and this data is
named Dref
Convert Dref to decimal
notation and obtain Dref'.
(Note)
Calculate D ', D ', D
19 1A 1B
D 'using following
1C
equations (decimal
calculation).
D '= Dref' + 8
19
D '= Dref' + 23
1A
D '= Dref' + 44
1B
D '= Dref' + 55
1C
Digital voltmeter
Order Page Address Data
8
9 F
10 F
11 F
12 F
Note: Refer to table 5-2-2 "Hexadecimal-decimal conversion
table".
Processing after Completing Adjustments:
Order Page Address Data
1 0

2. Alignment Check (FDD Unit)

Confirm that the FDD alignment is within the specifications. If
deviated, reading and writing data from and to floppy disk be-
come impossible.
Or compatibility of floppy disk with other machines can be lost.
Mode
Signal
Measurement Point
Measuring Instrument
Specified Value
Checking method:
1) Disconnect the adjusting remote commander.
2) Insert the alignment disk TFD2-1 (+) (+17.5 um).
3) Playback arbitrary signal and check that the playback picture
is normal.
4) Insert the alignment disk TFD2-2 (–) (–17.5 um).
5) Playback arbitrary signal and check that the playback picture
'and
is normal.
Power cord
(J-6082-223-A)
Fig. 5-1-20
5-21
Procedure
Convert D ', D
19
D 'to a hexadecimal number,
1C
and obtain D
19
D . (Note)
1C
19 D Press PAUSE button.
19
1A D Press PAUSE button.
1A
1B D Press PAUSE button.
1B
1C D Press PAUSE button.
1C
Procedure
01 00
PLAY
Alignment disks (TFD2-1 (+))
and (TFD2-2 (–)):
Arbitrary signal
Check on LCD screen
The playback pictures should be
normal
', D 'and
1A 1B
, D , D and
1A 1B