LG / GOLDSTAR P434I
Manual de Servicio

GOLDSTAR P 434 I
Matrix
Item See Model Book
6 6 6 6 6 6 Safety Notes ................................................................................................ P934 I Service Cables ............................................................................................ P934 I Mechanism Disassembly ........................................................................... P934 I Mechanism Adjustments ........................................................................... P934 I Mechanism Troubleshooting Guides ....................................................... P934 I Deck Exploded Parts View ........................................................................ P934 I

1
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.

U-View Limited
Cabinet Exploded View

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.

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 connected 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 XValue. 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 connected with GND. 2. Audio Circuit

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) Adjustment 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.

Cabinet Parts List
Location A43 A44 A45 OR A45 A46 250 260 266 267 268 269 270 275 280 283 284 300 320 330 452 459 462 Part No. 3721R-F004V 3501R-0278C 3501R-0690A 501-520B 3501R-0263E 217-570B 315-347B 321-738A 255-429A 255-359A 255-362A 321-743A 340-086A 3720R-F009K 3580R-0003E 442-681A 681-142E 258-728C 220-050A 353-051 A 353-046A 353-136A Description PANEL ASSY BOARD ASSY BOARD ASSY MODULE BOARD ASSY CASE FRAME BRACKET PLATE PLATE PLATE BRACKET HOLDER PANEL DOOR SPRING CORD PANEL COVER SCREW SCREW SCREW Specification FRONT SMPS PRE-AMP PRE-AMP(P401P) MAIN I TOP MAIN(60HR) ASSY HOUSING GND(M/F) SIDE GND PREAMP GND PROTECT DIGITRON FRONT CST DOOR H03WH2-F 2-0.75MM(2X0.5MH) ASSY DISTRIBUTOR BOTTOM SPECIAL(3X10 FZMY) SPECIAL (3X6 FZMY) SPECIAL(4.6X12.5 FBK)

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 synchronized signal is 416±50usec.

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