Panasonic NV-FJ623EG User manual

Service Manual
ORDER NO. VRD0202004C2
Video Cassette Recorder
lNV-FJ623EG/NV-FJ623EGY/NV-FJ628EE
Z-MECHANISM
© 2002 Matsushita Electric Industrial Co., Ltd. All rights reserved. Unauthorized copying and distribution is a
violation of law.

1. INTRODUCTION
This service manual contains technical information which will allow service
personnel to understand and service this model.
If the circuit is changed or modified, this information will be followed by
supplementary service manual to be filed with original service manual.
Note:
1. Adjustment procedures, Disassembly Procedures and Assembly
Procedures for Mechanism Chassis are separate volume from this service
manual./Please refer to the service manual for Z-Mechanism Chassis.
(Order No. VRD9802005C2)
2.
The Model No. is indicated on the Schematic Diagram and Circuit Board
Diagrams as follows.
Model No. Indication Mark
NV-FJ623EG (EG)
NV-FJ623EGY
(EGY)
NV-FJ628EE (EE)

2.1.1 REPLACING IC7702/EEPROM
When the EEPROM: IC7702 is replaced, applicable model code, option code and electrical adjustment data will
not be available.
Therefore, enter and/or adjust the necessary data after replacing IC7702 by referring following procedure.
STEP1.REPLACE THE IC7702
1. Remove the C.B.A. with Mechanism unit by referring the Disassembly procedure.
2. Disconnect the AC plug and replace the IC7702.
STEP2.INPUT THE MODEL & OPTION CODE
1. Set up the applicable model code and option code by ordering the following table.
Fig.S1 Service Secreen (sample)
PROCEDURE F.I.P. DISPLAY
Turn on the Service Mode
1.Press the FF key and the EJECT key simultaneously for more than 3 seconds.
Activate the Service Mode 2
2.While keep placing FF key, press the EJECT key in twice.
Activate the Entering Mode.
3.Press the EJECT key for more than 3 seconds.
Set the Mode 2.
4.Press the CH UP key in twice.
Display the Setting Code.
5.Press the POWER Button to turn the power on.
(Colon starts flashing)
Enter the Model and Option Code.
6.Service Screen is displayed on the monitor.
7.Set the applicable Model and Option code by using REW, PLAY, STOP and FF keys on theRemote Controller. (See Fig.S1 & S2)
Exit from Service Mode.
8.Press the POWER Button to turn the power off.
9. Press FF and EJECT keys simultaneously in 6 times.
(Normal Indication)

NOTE:
Since all electrical adjustments data is still not available, perform the Electrical Adjustment continuously.
Model No. Model
Code
Option Code 1
Option Code 2
Option Code 3
NV-FJ623EG/EGY
65
(41h)
125
(7Dh) 196 (C4h) 6 (6h)
NV-FJ628EE 70
(46h)
121
(79h) 196 (C4h) 6 (6h)
Fig. S2 Model Code & Option Code

2.1.2 CYLINDER UNIT REPLACEMENT
1. CYLINDER UNIT REPLACEMENT
A. Remove the mechanism unit from MAIN C.B.A./Chassis by referring “SECTION 2. Disassembly
Procedure”.
B. Remove the 3 screws (A) of the CYLINDER UNIT with a screw driver.
C. Unlock the 4 locking tabs (B) and disconnect the Cylinder flexible card from the FPC Holder.
D. Remove the CYLINDER UNIT.
CAUTION:
Handle the Cylinder flexible card with care. When it damaged, you should replace whole Cylinder
unit.
Fig. S3
2. UPPER CYLINDER DISASSEMBLY
A. Remove 2 screws (A).
B. Remove the Cylinder Stator Unit.
C. Remove 2 screws (B).
D. Remove the Cylinder Rotor Unit.
E. Loose Hex screw (C) (1.5 mm) and remove the CYLINDER RETAINER.
F. Remove the Upper Cylinder.
Fig. S4

3. UPPER CYLINDER ASSEMBLY
When reassembling, perform the steps in the reverse order.
Notes:
A. Install the Cylinder Retainer so that the 2 holes on top of the Cylinder Retainer are at right angles
with the P3502 Connection.
B. Tighten the Hex screw (C) (1.5 mm) while pressing down on top of the Cylinder Retainer.
Fig. S5

C. Install the Cylinder Rotor Unit so that the inner hole of the Cylinder Rotor Unit fits to the small
projection (D) on top of the Upper Cylinder.
D. Tighten 2 screws (B).
Fig. S6
E. install the Cylinder Stator Unit.
F. Tighten 2 screws (A).
Fig. S7
G. Confirm the PG SHIFTER ADJUSTMENT with the alignment tape (PAL: VFJ8125H3F) and adjust
it if necessary.

2.1.3 CHECKING OF MAIN C.B.A.
When servicing the MAIN C.B.A., take out the MAIN C.B.A. and mechanism from the frame and turn over.
Fig. S8
2.1.4 FLAT CARD CABLE INSTALLATION
When installing the Flat Card Cable on the connector, install the Flat Card Cable with the cable contacts facing
the connector contacts.
Fig. S9

2.2 REMOVAL OF CASSETTE TAPE
There are 2 ways to remove a cassette tape.
1. Service Information Display Operation
A. Press the FF and EJECT keys simultaneously for 3 seconds and set the Service Mode 7.
B. Press STOP key in order to rotate the Loading Motor for unloading operation. (Pay an attention of
tape slack)
2. Manual Operation
A. Disconnect the AC Mains Lead and remove the Top Panel.
B. Rotate the Main Cam Gear clockwise until the Loading Posts move to fully unloaded position as
shown in Fig. S10 . (Tape is remaining)
Fig. S10
C. Rotate the Capstan Motor clockwise from the bottom side to take up the tape.
Fig. S11
D. Rotate the Main Cam Gear clockwise until the cassette tape is ejected.

2.3 INTRODUCTION OF VIDEO HEAD CLEANING CASSETTE/
(POLISHING TYPE)
1. We are pleased to introduce Panasonic Video Head Cleaning Cassette, VFK0923FT [for service purposes]
and VFK0923FSE [ for end users] for all VHS/SVHS VCP and VCR.
2. These cleaning cassettes are exclusive removing the hard and sticky clogging on video heads.
3. These improve the efficiency of video head cleaning service and shortening cleaning time for end users.
Note:
The tape material itself is the same in both types.
VFK0923FT
(For Service usage)
Type of Cassette Full VHS Cassette
Cleaning Time 10 Seconds/Time
Tape Length 20 m
Usability in a Path
180 Times
VFK0823FSE
(For end users)
Type of Cassette Full VHS Cassette
Cleaning Time 10 Seconds/Time
Tape Length 3.34 m
Usability in a Path
30 Times

2.4 SELF-DIAGNOSIS RESULT DISPLAY
The "SELF-DIAGNOSIS RESULT DISPLAY & MEMORY function is built in this VTR.
It means that when the VCR detects undesirable condition, it can be displayed a “Error code (Two numbers from
the right)”with Service Mode 2.
Since the "Error code" is stored in the EEPROM, it can be displayed although after disconnected the AC leads. It
can be displayed with Service Mode 2.
(If a second error had been detected, only the most recent error is displayed. )
For more details, refer to the Service Manual for Z-Mechanism Chassis Order number VRD9802005C2.
Fig. T1 Self-Test indication Display
INDICATION
CAUSE REMEDY/CHECK
01 After cylinder lock is detected, the cylinder does not start rotating again
even after tape unloading. Check the cylinder motor drive circuit.
02 Cassette tape is not wound up during the tape unloading except EJECT
mode. Check the capstan motor drive circuit.
03 Mechanism locks during mode transition except EJECT mode. 1. Check the loading motor drive circuit.
2. Check the mechanism phase alignment.
3. Check the mode switch.
04 Mechanism locks during tape unloading. 1. Check the loading motor drive circuit.
2. Check the mechanism phase alignment.
06 Mechanism locks after tape unloading in EJECT mode. 1. Check the loading motor drive circuit.
2. Check the mechanism phase alignment for cassette holder unit.
07 During recording mode, recording signal is less than the normal condition. Protection of the over-current flowing in transistor which produces the power
supply for recording mode.
08 Recording circuit works except recording mode. Check the recording circuit.
16 Cylinder lock detection. Check the cylinder unit and the cylinder motor drive circuit.
17 Supply reel mechanism lock detection Check the supply reel mechanism and the supply reel circuit.
18 Take-up reel mechanism lock detection Check the Take-up reel mechanism and the Take-up reel circuit.
2* PG shifter automatic adjustment error. Check the servo/system control circuit and the cylinder unit.

3.1.1 DISASSEMBLY FLOW CHART
This flow chart indicates disassembly steps of the cabinet parts and the circuit boards in order to find the
necessary items for servicing.
When reassembling, perform the steps in the reverse order.
Fig. D1

3.1.2 DETAIL OF DISASSEMBLY METHOD
1. REMOVAL OF THE TOP PANEL
Fig.D2
2. REMOVAL OF THE FRONT PANEL UNIT
Fig. D3
3. REMOVAL OF THE MECHANISM UNIT
Note:
A. Keep pressing 2 stoppers on Cassette Holder Plate and Press Cassette Holder Plate to the rear.
B. Remove the Mechanism Unit after bend the Cylinder Shield in the direction of the arrow.
Fig. D4
Remove
4 Screws (A)
Unlock
7 Tabs (B)
Remove
Screw (C)
Remove
3 Screws (D)
Remove
2 Screws (E)

4. REMOVAL OF THE MAIN C.B.A.
Fig. D5
NOTE:
Before mounting the MAIN C.B.A. onto the frame, be sure to confirm that the insulation sheet is mounted
on the frame as shown in Fig. D6 .
Fig. D6
Remove
4 Screws (F)
Unlock
4 Tabs (G)

5. SERVICING POSITION
Fig. D7
3.2 MECHANICAL ADJUSTMENT PROCEDURES
Refer to the Service Manual for Z-Mechanism Chassis./(Order No. VRD9802005C2)

3.3.1 TEST EQUIPMENT
The following equipments are required for Electrical Adjustments.
1. Dual-Trace Oscilloscope
¡Voltage Range: 0.005-5V/div
¡Frequency Range: DC-35MHz
¡Probes: 10:1 / 1:1
2. Frequency Counter
¡Frequency Range: 0-10MHz
¡Probes: 1:1
3. Universal Counter
4. Digital Volt Meter (D.V.M.)
5. Video Sweep Generator
6. Sinewave Generator
7. Video Pattern Generator
8. Monitor TV
9. DC Power Supply
10. VHS Blank Tape
11. VHS Alignment Tape
¡Parts No.: VFJ8125H3F(PAL)
3.3.2 VCR SETTING
When no indication in the procedure, set each selector as follows:
1. TAPE SPEED: SP
2. CHANNEL: AV1
(Set to signal input terminal number)

3.3.3 ADJUSTMENTS
3.3.4 PG SHIFTER ADJUSTMENT/(AUTOMATIC)
Fig.E1 Fig.E2
CONDITION: BURST SIGNAL OFF / 75 ohm TERMINATED
PROCEDURES FIP DISPLAY
Press the FF and EJECT Keys
simultaneously for 3 seconds.
Press the FF and EJECT Keys
simultaneously twice.
Press the EJECT key for 3 seconds.
Press the CH UP key once.
Insert the Alignment cassette tape. (PAL:VFJ8125H3F)
When the sequence of the automatical adjustment has been terminated, the following action has been made.
*SUCCEED: The cassette tape is ejected.
*ERROR : The "F2"is displayed on the FIP.
(Check the Servo/Syscon circuit and Cylinder unit.)
Release the Service mode by pressing the EJECT and FF keys simultaneously in 6 times until the FIP becomes normal indication.
Fig. E3

3.3.5 AI FUNCTION ADJUSTMENT (AUTOMATIC)
3.3.6 VIDEO FREQUENCY RESPONSE ADJUSTMENT
PROCEDURES FIP DISPLAY
Press the FF and EJECT Keys
simultaneously for 3 seconds.
Press the FF and EJECT Keys
simultaneously twice.
Press the EJECT key for 3 seconds.
Press the CH UP key in 3 times.
Insert the blank cassette tape.
(The adjustment is automatically started.)
When the sequence of the automatical adjustment has been terminated successfully, the VCR goes to STOP mode.
Release the Service mode by pressing the EJECT and FF keys simultaneously in 6 times until the FIP becomes normal indication.
Fig. E4
PROCEDURES FIP DISPLAY
Input the Video sweep signal.
(See Fig.E1)
Press the FF and EJECT Keys
simultaneously for 3 seconds.
Press the FF and EJECT Keys
simultaneously twice.
Press the EJECT key for 3 seconds.
Press the CH UP and/or CH DOWN key until "11" is displayed on FIP.
Insert the Self-recorded tape and playback it. (SP/LP/EP mode)
Connect the Oscilloscope to:
*CH1....Video Out (TW3002).
*CH2....V.FREQ.(TW6002)
Press the "4" key on the remote controller.
(Confirm that TW6002 becomes high(5V)).
Adjust the Frequency response by pressing the "2"(increase) and/or "8"(decrease) key on the Remote Controller. (See Fig.E2)
Store the Adjusted value by pressing the "5" key on the Remote Controller.
Release the Service mode by pressing the EJECT and FF keys simultaneously in 6 times until the FIP becomes normal indication.
Fig. E5

3.3.7 LOCATION OF TEST POINTS& CONTROLS
3.3.8 CIRCUIT BOARD LAYOUT

3-1. ABBREVIATIONS
443NT [L]
A. COMP
A. COMPO
A. D.P [L]
A. D/L [L]
A. DEF [S]
A. DEF [S] [L]
A. DUB P [L]
A. DUB [H]
A. ERASE
A. H. SW
A. HEAD [R]
A. HEAD [W]
A. IN [L]
A. IN [R]
A. MUT [H]
A. MUTE [H]
A. OUT [L]
A. OUT [R]
A. RF OUT
A/VS/S. DATA
AC ONLINE
AC. O/EE. H
AFC S C
AFC [S]
AFC. DEF
ARFC OUT
ART. V
ART. V. MM
ART. V/H/N
AT. V/H/N
ATSW/TEST/NOR/SE
AUDIO IN [L]
AUDIO IN [R]
AUDIO OUT [L]
AUDIO OUT [R]
AUDIO SELECT [H]
AUDIO. L
AUDIO. R
AV CNT
AV CTL
AV CTL/S. CLK
AV. C.M.
AVCNT/METER. R
AVSW/METER. L
B MODE. H
B.G.P
BACKUP 5V
BAND. U.E.
BANDVL. D
BI/MI [L]
4.43 NTSC L
AUDIO COMPONENT SIGNAL
AUDIO COMPONENT SIGNAL
AUDIO DUBBING PAUSE L
AUDIO DUBBING PAUSE L
AUDIO DEFEAT
AUDIO DEFEAT
AUDIO DUBBING PAUSE L
AUDIO DUBBING H
AUDIO ERASE
AUDIO HEAD SWITCHING PULSE
AUDIO HEAD (REC)
AUDIO HEAD (PLAY)
AUDIO INPUT (L)
AUDIO INPUT (R)
AUDIO MUTE H
AUDIO MUTE H
AUDIO OUTPUT (L)
AUDIO OUTPUT (R)
AUDIO RF SIGNAL OUTPUT
AV SW/SERIAL DATA
AC ONLINE
AC ONLINE/EE H
AFC S CURVE
AFC S CURVE
AFC DEFEAT
AUDIO RF SIGNAL OUTPUT
ARTIFICIAL VERTICAL SYNC SIGNAL
ARTIFICIAL VERTICAL SYNC
SIGNAL MONO MULTI
ARTIFICIAL VERTICAL SYNC
SIGNAL H/NORMAL
ARTIFICIAL VERTICAL SYNC SIGNAL
TEST/NORMAL/SERVICE
AUDIO INPUT (L)
AUDIO INPUT (R)
AUDIO OUTPUT (L)
AUDIO OUTPUT (R)
AUDIO SELECT H
AUDIO (L)
AUDIO (R)
AV CONTROL
AV CONTROL
AV CONTROL/SERIAL CLOCK
AV CONTROL MODE
AV CONTROL/LEVEL METER (R)
AV SW/LEVEL METER (L)
B MODE H
BURST GATE PULSE
BACK UP 5V
BAND U
BAND VL
BILINGUAL/MIX L
BIL
BIL [L]
BIL. [H]
BIL/M1 [L]
BS CLOCK
BS DATA
BS LCH IN
BS MIX [H]
BS MON [H]
BS MONI [H]
BS RCH IN
BS VIDEO
BS VIDEO/BS1
BS [H]
BS. LEVEL
BS. M [H]
BS/VTR [H]
BUS CLK
BUS LSN
BUS TLK
BUZZER
CAP EC
CAP M GND
CAP. ET
CAP. FG1
CAP. FG2
CAS. SW
CCN
CCP
CHM
CHP
CINEM [L]
CINEMA [L]
CINEMA/MIX
CKL
CKS
CL
CLK
CLK (C.G)
CLOCK. IN
CLP
COL/B/W/NOR
COLOR [H]
CONV
CS
CTL GND
CTL HEAD [
+
]
CTL HEAD [
−
]
CTL [
+
]
CTL [
−
]
CUE BIAS
CURRENT LIM
CYL ET
BILINGUAL
BILINGUAL L
BILINGUAL H
BILINGUAL L
BS CLOCK
BS DATA
BS L CHANNEL INPUT
BS MIX H
BS MONITOR H
BS MONITOR H
BS R CHANNEL INPUT
BS VIDEO SIGNAL
BS VIDEO SIGNAL
BS H
BS LEVEL
BS MONITOR H
BS/VTR H
BUS CLOCK
BUS LISTEN
BUS TALK
BUZZER
CAPSTAN TORQUE CONTROL
CAPSTAN MOTOR GND
CAPSTAN TORQUE CONTROL
CAPSTAN FG1 PULSE
CAPSTAN FG2 PULSE
CASSETTE SW
PLAYBACK CONTROL SIGNAL (−)
PLAYBACK CONTROL SIGNAL (+)
CONTROL SIGNAL (
+
)
CONTROL SIGNAL (
−
)
CINEMA L
CINEMA L
CINEMA/MIX
RATCH LOCK
SHIFT LOCK
CLOCK
CLOCK
CLOCK
CLOCK INPUT
CLAMP
COLOUR/BLACK & WHITE/NORMAL
COLOUR H
CONVERTOR
CHIP SELECT
CONTROL GND
CONTROL HEAD (
+
)
CONTROL HEAD (
−
)
CONTROL HEAD (
+
)
CONTROL HEAD (
−
)
CUE BIAS
CURRENT LIMMITER
CYLINDER TORQUE CONTROL
SECTION 3
BLOCK DIAGRAMS & SCHEMATIC DIAGRAMS