Panasonic TC-29G12P HUM Verification, Synthetizer Adjustments, Audio Output Check UP

Service Adjustments and Calibrations TC-20G12P / TC-29G12P / TC-29G12PU

HUM VERIFICATION

REQUIRED EQUIPMENTS / CONNECTIONS: JIG filter: Connect between the speaker’s terminals. Oscilloscope: Connect between the JIG Filter and GND. Function Tester: Connect to PC-Board.

		JIG filter
	3.3mH	3.3mH
(+)		(+)
SPK terminals	0.3μF	Osciloscope
		150Ω
(_)		(_)

SYNTHETIZER ADJUSTMENTS

REQUIRED EQUIPMENTS / CONNECTIONS:

Frequency Counter: TP42 – GND

PREPARATION:
1. CLOCK CORRECTION	128 (DAC: S0)

PROCEDURE:

1.Measure TP42 for period.

2.Adjust the register (DAC:S0) based in the next formula: (DAC: S0)=128+0.901x106 {1-1/(244.1406xTP42)}

PREPARATION:
1.	VOLUME	Max.
2.	AI SOUND	OFF
3.	SPEAKER SW	ON

PROCEDURE:

1.Apply a COLORBAR pattern without audio modulation (70±5dB, 75Ω open, P/S 10dB)

2.Check if the hum level is less then 1.5Vp-p

3.When the hum level be bigger 1.5Vp-p, use the JIG filter and check if the hum level is less that 0.5Vp-p

HUM level

AUDIO OUTPUT CHECK UP

REQUIRED EQUIPMENTS / CONNECTIONS:

RMS Voltmeter:

Input Cable: VAO “L” and “R” Terminals.

Ground Cable: GND.

PREPARATION:
1.	VOLUME	Maximum
2.	AI SOUND	OFF
3.	SPEAKER SW	OFF

PROCEDURE:

1.Apply a 7.5KHz standard audio signal modulated with 1KHz, and 30% deviation.

2.Check if the RMS Voltmeter shows a voltage 430±150mVrms between “L” and “R” terminals.

3.Or measure TP42 for frequency.

4.Adjust the register (DAC: S0) based in the next formula:

(DAC: S0) =128+0.901x106 {(244.1406-TP42)/244.1406}

DEFLECTION CIRCUIT CHECKUP

REQUIRED EQUIPMENTS / CONNECTIONS: Voltmeter (50KV): Connect to CRTanode.

PREPARATION:
1.	CONTRAST	Minimum
2.	BRIGHT	Minimum

PROCEDURE:

1.Apply a BRIGHT pattern and adjust SCREEN and BRIGHT until the back-line disappear

2.Check if the high voltage is [A].

• TC-20G12P [A] = 26,25±1,25kV

• TC-29G12P/TC-29G12PU [A] = 29,25±1,25kV

3.Return the SCREEN and BRIGHT adjust to original positions.

4.Apply a CROSSHATCH pattern.

5.Check exist vertical and horizontal lines distortions when the user contrast adjust is on the maximum , while the black level is optimized with the crosshatch bright signal.

DEFLECTION CIRCUIT ADJUSTMENT

The deflection circuit adjust of chassis BR1L/BR1D is done in four steps:

1. H-CENTER

2. H-WIDE

3. V-HEIGTH

4. V-CENTER

STEP 1 – H-CENTER ADJUSTMENT

PROCEDURE:

1.Apply a MONOSCOPE pattern.

2.Adjust CONTRAST on maximum, and BRIGHT on center.

3.Adjust the horizontal center (DAC:Cc) to center PHILIPS pattern on the CRT.

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