Goldstar P 434 I, Manual

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1
GOLDSTAR P 434 I
U-View Limited
Matrix
Item See Model Book
Safety Notes ................................................................................................ P934 I 6
Service Cables ............................................................................................ P934 I 6
Mechanism Disassembly ........................................................................... P934 I 6
Mechanism Adjustments ........................................................................... P934 I 6
Mechanism Troubleshooting Guides ....................................................... P934 I 6
Deck Exploded Parts View ........................................................................ P934 I 6
Electrical Adjustments
Electronic Test Equipment
Oscilloscope
Video Signal Generator
Level Meter
+ Driver
Test Tape (SP)
Recording Tape
Digital Multimeter
Monitor Scope
Power Supply
ABBREVIATIONS
SPEC: Specification
M.P: Measurement Point
A.P: Adjustment Point
1. Servo Circuit
1) PG Adjustment
Purpose:
For the phase dividing of the Video A,B heads
with 180 and the exact tracing of each track to
meet head switching point with VHS Spec.
Fig. 3-1
1-1) Record PG Adjustment
MODE: Record
SPEC: 416
±
50usec
M.P: TP302 (H.SW) JK701 Pin(1) (Video Out)
A.P: VR502
1-2) Playback PG Adjustment
MODE: Playback
SPEC: 6.5H
±
0.5H (41 6usec, 1 H=64usec)
M.P: TP302 (H.SW) JK701 pin (Video Out)
A.P: VR501
1-1) Record PG Adjustment
Procedure:
a. Set the VCR to AN mode.
b. Connect CH-1 terminal of oscilloscope to
TP302 (H.SW) and CH-2 terminal to video out
terminal (JK701 pin(1) of VCR.
c. Input the Video signal to Video Input Jack.
d. Record in PAL SP mode.
e. Trigger the complex Video signal of CH2 to
CH-1 (H.SW), and adjust VR502 so that the
distance from A(B) head selection point of H.SW
signal to the starting point of Vertical synchro-
nized signal is 416
±
50usec.
Reference:
1. Record PG Adjustment is proceed in the
Record mode and must be input video signal.
2. The deviation between A/B Head Adjustment
location should be within i-0.5H (32usec).
3. The deviation between the specification of
adjustment and the practical measurement
value should be within t-S0usec.
4. Oscilloscope and VCR set should be con-
nected with GND.
5. When the Power Assy of set is changed, you
should be readjust Record PG.
1-2) Playback PG Adjustment
Procedure
a. Playback a PAL SP test tape.
b. At this time, the ATR’ is lighting, after pressing
the A.TR (+) or A.TR(-) and adjust the X-
Value.
c. Connect CH-1 terminal of oscilloscope to
TP302(H.SW) and CH-2 terminal to Video Out
terminal (JK701 pin(1) of VCR.
d. Trigger the complex Video signal of CH2 to
CH-1 (H.SW), and adjust VR501 so that the
distance from A(B) head selection point of
H.SW signal to the starting point of Vertical
synchronized signal is 6.5H (416usec, 1H=
64usec).
e. The conversion of A/B Head SW signal uses
the Polarity Invert Knob of oscilloscope.
Reference:
1.
±
PG adjustment is proceed in the state of
maximum RF level and locked servo system
(MTR Mode).
2. The deviation between A/B Head Adjustment
location should be within
±
0.5H (32usec).
3. The deviation between the specification of
adjustment and the practical measurement
value should be within
±
0.5H (32usec).
4. Oscilloscope and VCR set should be con-
nected with GND.
2. Audio Circuit
1) Record Bias Adjustment
MODE: Record
SPEC: 3.0mW
±
0.2mV RMS
M.P: W105(+) W106 (-)
A.P: VR401
Purpose:
This is adjusting the bias current to specification
in recording.
Procedure:
a. Connect (+) terminal of the Level Meter to
W105 (+).
b. Connect (-) terminal of the Level Meter to
W106 (-).
c. Confirm that the Oscillation Voltage is
3.0mV
±
0.2mV RMS.
d. At this time, adjust VR401 and make the
oscillation voltage fit to specification.
3.Tuner/IF Circuit
1) VCO (Voltage Controlled Oscillation)
Adjustment
MODE: PAL I (38.9MHz)
SPEC: DC 2.5
±
0.1V
M.P: P7M02 pin(5)(AFC CTL)
A.P: T750AFC
(Automatic Frequency Control) (VCO COIL)
Procedure:
a. Connect as shown in Fig. 3-2.
Fig. 3-2.
b. Input the PAL I 38.9MHz (Strength of input
electric field: 75
±
5dBu) signal Out Terminal of
TV RF Pattern GEN instrument.
c. Confirm that the video signal is Output by
connect oscilloscope to P7M01(2)PlN.
d. Adjust VCO coil T750 so that the voltage of
P7M02 pin (5) became DC 2.5
±
0.1V.
2) RF AGC (Automatic Gain Control) Adjust-
ment
MODE: PAL B/G (E11CH)
SPEC: 5.5
±
0.1V p-p
M.P: W393
A.P: VR701
Procedure:
a. Be tuning PAL B/G E11CH (216.25MHZ)
(strength of input electric field: 70
±
1dBu).
b. Connect the Digital Voltmeter to Tuner AGC
PIN.
c. Adjust VR701 so that the digital voltmeter is
5.5
±
0.1Vp-p.
Reference:
Maintain the input gain in adjusting AGC
faithfully.
Location Part No. Description Specification
A43 3721R-F004V PANEL ASSY FRONT
A44 3501R-0278C BOARD ASSY SMPS
A45 3501R-0690A BOARD ASSY PRE-AMP
OR
A45 501-520B MODULE PRE-AMP(P401P)
A46 3501R-0263E BOARD ASSY MAIN I
250 217-570B CASE TOP
260 315-347B FRAME MAIN(60HR)
266 321-738A BRACKET ASSY HOUSING
267 255-429A PLATE GND(M/F)
268 255-359A PLATE SIDE GND
269 255-362A PLATE PREAMP GND
270 321-743A BRACKET PROTECT
275 340-086A HOLDER DIGITRON
280 3720R-F009K PANEL FRONT
283 3580R-0003E DOOR CST
284 442-681A SPRING DOOR
300 681-142E CORD H03WH2-F 2-0.75MM(2X0.5MH)
320 258-728C PANEL ASSY DISTRIBUTOR
330 220-050A COVER BOTTOM
452 353-051 A SCREW SPECIAL(3X10 FZMY)
459 353-046A SCREW SPECIAL (3X6 FZMY)
462 353-136A SCREW SPECIAL(4.6X12.5 FBK)
Cabinet Exploded View
Cabinet Parts List