FUNAI Service manual / Схема, сервісна інструкція Service manual & schematics

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FUNAI SERVICE MANUAL

20" COLOR TELEVISION

MS-20A MKIII

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Note:

Electrical adjustments are required after replacing circuit components. It is important to perform these adjustments only after all repairs and replacements have been completed. Also, do not attempt these adjustments unless the proper equipment is available.

Test Equipment Required:

1. Monoscope
2. PAL and SECAM Pattern Generator

3. IF Sweeper and Scope

4. Spectrum Analyzer

5. DC Volt Meter

6. Oscilloscope: Dual Trace with 10:1 probe

7. Color Analyzer

8. AM S.S.G. (Standard Signal Generator)

How to Set Up the Service Mode:

Preset Mode: Press Picture Select button on the remote control unit, then press the number "1" button.

Brightness ------ Center Color ----- Center Contrast ----- Approx 70%

All adjustment procedures must be performed in order of numbering.

Operate the unit more than 20 minutes.

1. Power Supply DC Voltage Adjustment

Purpose: To get correct voltage.

Symptom of Misadjustment: The picture is dark and unit does not operate correctly.

Test Point	Adjustment Point	Input
R621 TP1 (GND)	VR621	Monoscope Pattern
Equipment		Spec.
Monoscope DC Volt Meter		DC +112±0.5V

Reference Notes: R621, TP1, VR621 --- Main PCB

• Adjust VR621 so that the + of C623 becomes DC +112±0.5V.

2. VCO Adjustment

Purpose: To set the IF (Intermediate Frequency).

Symptom of Misadjustment: Proper picture cannot be obtained.

Test Point	Adjustment Point	Input
T214	Г214 T214 —
Equipment		Spec.
Spectrum Analyzer		38.0±0.05MHz
Connections of M. EQ.

Reference Notes: T214 ---- Main PCB

1. Short C214.

2. Set the Spectrum Analyzer as shown in the above table. (Make a loop by connecting both probes of the Spectrum Analyzer and bring the loop near T214 to pick up the leakage wave.)
3. Adjust T214 for reading 38.0±0.05MHz on the Spectrum Analyzer.

<without Spectrum Analyzer>

1. Turn T214 in both directions, right and left, far enough to find the point where Noise Bands or Beats appear on the TV Screen.
2. After finding those points in both directions, adjust T214 so that it is exactly half-way between those two points.
3. After the above adjustment, tune in another Local Broadcast. Then confirm that no Noise Bands or Beats appear on the TV Screen.

L8406DC

Page 3

3. AFT Adjustment

Purpose: To operate AFT correctly

Symptom of Misadjustment: AFT does not work correctly and/or synchronization is faulty.

Reference Notes: Q201, T211, TP1, TP7 --- Main PCB

1. Input the 38.0MHz (90dBμV) no modulating signal from Q201 base.
2. Turn the core inside of T211 counterclockwise until the top of core is the same height as metal case.
3. Turn the core of T211 clockwise and find the point where the voltage drops from approximately 5.5V to 0V immediately on the oscilloscope.
4. Turn the core of T211 little by little and find the point where DC +3.4±0.2V is obtained between the area mentioned in step 3.

Note: Before the adjustment, confirm that the tuner output does not have any noise except white noise.

4. AGC Adjustment

Purpose: Set AGC (Auto Gain Control) Level.

Symptom of Misadjustment: AGC does not synchronize correctly when RF Input Level is too weak and picture distortion may occur if it is too strong.

Test Point	Adjustment Point	Input
TP8 TP1 (GND)	VR211 PAL Color Ba
Equipment		Spec.
PAL Pattern Generator DC Volt Meter		DC +4.5±0.1V

Reference Notes: TP1, TP8, VR211 --- Main PCB

1. Receive the PAL Color Bar signal for channel 2 (48.25MHz). (RF Input Level: 80dBuV)

2. Adjust VR211 so that the voltage of TP8 becomes DC +4.5±0.1V. (ALPS TUNER)

5. SIF Adjustment

Purpose: To set the SIF (Sound Intermediate Frequency).

Symptom of Misadjustment: Not sound.

Reference Notes: TP1, TP9, T212, T213 --- Main PCB

1. Connect SIF Sweeper & Scope shown in the above table.
Adjust T212 (SIF=6.5MHz) so that the center mark will be center of SIF waveform and its waveform is straight.
Adjust T213 (SIF=5.5MHz) so that the center mark will be center of SIF waveform and its waveform is straight.

4. Repeat 2 & 3.

6. Bell Filter Adjustment

Purpose: To adjust the center frequency of SECAM bell filter.

Symptom of Misadjustment: The color will be reversed when the SECAM signal is entered.

Test Point	Adjustment Point	Input
TP2 TP1 (GND)	T404	SECAM Color Bar
Equip	oment	Spec.
SECAM Patte Oscillo	ern Generator oscope	See below
C	Connections of	M. EQ.
		Oscilloscope
Main PCB	TP2 TP1 (GND) D651	Ext. CH+ Trig. ○ 0 5mV/div (AC) 10µS/div

Reference Notes: D651, TP1, TP2, T404 --- Main PCB Adjust T404 so that the waveform will be flat shown in the above figure.

7. SECAM Ident Coil Adjustment

Purpose: To adjust the peak value of SECAM Ident signal.

Symptom of Misadjustment: The display is not colored when the SECAM signal is entered.

Test Point Adjustment Point		Input
TP5 TP1 (GND)	T403	SECAM Color Bar
Equipment		Spec.
SECAM Pattern Generator Oscilloscope		See below

Reference Notes: TP1, TP5, T403 --- Main PCB

1. Set oscilloscope to 10:1 probe, 0.2V/div (DC) and Range 5µS/div.

2. Adjust T403 so that the TP5 will be peak DC Voltage.

L8406EA

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8. SECAM Demodulate Coil Adjustment

Purpose: To adjust the level of R-Y and (B-Y) color difference signal.

Symptom of Misadjustment: The Red, Green and Blue will be unbalanced.

Reference Notes:

D651, TP1, TP3, TP4, T401, T402 --- Main PCB
1. Adjust T402 with core driver so that (A) becomes center of (B) as shown in the above table. (TP3)
2. Adjust T401 with core driver so that (A) becomes center of (B) as shown in the above table. (TP4)

9. 1H Delay Line Adjustment

Purpose: To get correct 1H delay line when the PAL signal is entered.

Symptom of Misadjustment: The Anti-PAL signal part is colored when the Philips Pattern is entered. Each scanning line is colored on the color bar.

Reference Notes:

D651, TP1, TP6, T301, VR301 --- Main PCB
Adjust VR301 and T301 so that the amplitude at Anti-PAL signal part becomes minimum (no color) and the waveform at the color bar part is not seen in double ("Venetian Blind" does not appear at the color bar signal part).

10. Black Level Adjustment

Purpose: To obtain optimum picture quality.

Symptom of Misadjustment: Black color may not be properly displayed (lighter or darker).

Reference Notes: TP1, TP6, VR351 --- Main PCB

1. Preset the picture control to initial position.

2 Receive the Black Baster pattern

3. Adjust VR351 so that the TP6 becomes DC +3.2±0.05V as shown in the above table. (TP6 waveform)

11. Cut Off Adjustment

Purpose: To adjust the beam current of Red, Green, Blue and screen voltage.

Symptom of Misadjustment: White color may be reddish, greenish or bluish. When the screen voltage is too high, the scanning line is appeared on the screen.

Reference Notes:

VR451, VR452, VR453, VR454, VR455 --- CRT PCB Screen-VR --- Main PCB (FBT)
1. Degauss the CRT using Degaussing Coil..
2. Set the Screen-VR to minimum. (Counterclockwise)
3. Set the drive VRs (VR454, VR455) to mechanical center, and cut off VRs (VR451, VR452, VR453) to 10 o'clock position.
4. Short the Emitter and Collector of Q125. (Horizontal One Line)
5. Slowly turn the Screen-VR (FBT) to the point where horizontal line is just visible.
6. Adjust VR451 (R. Cut Off), VR452 (G. Cut Off) and VR453 (B. Cut Off) so that horizontal line becomes pure white.
7. Re-adjust the Screen-VR (FBT) to the point where horizontal line is just visible.
8. Open the Emitter and Collector of Q125.

Note: Confirm that White Balance Adj. is correct after this adjustment, and attempt White Balance Adj. if needed.

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12. White Balance Adjustment

Purpose: To mix red, green and blue beams correctly for pure white.

Symptom of Misadjustment: White becomes bluish or reddish.

Test Point	Adjustment Point	Input
Screen VR454 VR455		White Raster (APL 100%)
Equip	Spec.
Pattern Generator Color Analyzer		See below

Reference Notes: VR454, VR455 --- CRT PCB

1. Degauss the CRT using Degaussing Coil.

2. Set the color analyzer to the CHROMA mode and after zero point calibration, bring the optical sensor into close contact with center on the CRT surface.
3. Adjust VR454 (R. DRIVE) and VR455 (B. DRIVE) so that the respective chroma temperatures becomes 8000K-10MPCD (x : 0.300 / y : 0.290) ±3%.

Note: Confirm that Cut Off Adj. is correct after this adjustment, and attempt Cut Off Adj. if needed.

13. Sub Bright Adjustment

Purpose: To get proper brightness.

Symptom of Misadjustment: Proper brightness cannot be obtained by adjusting the Brightness Control.

Reference Notes: Screen-VR --- Main PCB (FBT)

Adjust Screen-VR so that the level of dark gray bar (as shown above) is just visible. Note: Use the Gray Scale Signal without set up.

14. Focus Adjustment

Purpose: Set the optimum Focus

Symptom of Misadjustment: Blurred images are shown on the display.

Test Point	Adjustment Point	Input
Screen Focus VR		Monoscope Pattern
Equipment		Spec.
Monoscope		See below

Reference Note: Focus VR --- Main PCB (FBT)

Adjust Focus-VR (FBT) to be obtained clear picture.

15. V. Position & Size Adjustment

Purpose: To get correct vertical position and size of screen image.

Symptom of Misadjustment: Vertical position and size of screen image may not be properly displayed.

Test Point	Adjustment Point	Input
Screen	VR501, VR521	Monoscope Pattern
Equipment		Spec.
Monoscope		See below

Reference Note: VR501, VR521 --- Main PCB

1. Adjust VR521 so that the top & bottom of Monoscope pattern will be equal.
2. Adjust VR501 so that the vertical size will be 90±5% of Monoscope Pattern and the circle is round.

16. H. Position & Size* Adjustment

Purpose: To get correct horizontal position and size of screen image.

Symptom of Misadjustment: Horizontal position and size of screen image may not be properly displayed.

Test Point	Adjustment Point	Input
Screen	VR331 , L551	Monoscope Pattern
Equip	Spec.
Mono	See below

Reference Note: VR331, L551 --- Main PCB

1. Adjust VR331 so that the right & left of monoscope pattern will be equal.
2. Adjust L551 so that the horizontal size will be 90±5% of Monoscope Pattern and the circle is round.
* Only model with L551. (Size Coil)

BLOCK DIAGRAM

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SCHEMATIC DIAGRAMS / PCB'S AND TEST POINTS

Standard Notes

Warning

Critical components having special safety characteristics are identified witha A by the Ref. No in the parts list and enclosed within a broken line * (where several critical components are grouped in one area) along with the safety symbol A on the schematics or exploded views

Use of substitute replacement parts which do not have the same specified safety characteristics may create shock fire or other hazards

Under no circumstances should the original design be modified or altered without written permission from Funai Electric Company, Funai assumes no liability.

express or implied arising out of any unauthorized modification of design. Servicer assumes all liability.

Notes:

① Do not use the part number shown on these drawings for ordering. The correct part number is shown in the parts list, and may be slightly different or amended since these drawings were prepared.
② All resistance values are indicated in ohms (K=10³) M=10⁶).
3 Resistor wattages are 1/5W or 1/6W unless otherwise specified.
④ All capacitance values are indicated in μF (P=10^- ⁶uF).

							(
Pin No.	IC101	IC102	IC201	IC501	IC601	IC701	IC801
1	2.4	0.0	2.1	0.0	0.0	6.0	11.1
2	4.4	0.0	6.0	13.7	47.5	6.1	5.0
3	4.9	0.0	4.2	0.1	0.0	1.3	0.0
4	3.7	0.0	2.7	27.3	0.6	1.3	7.5
5	1.2	4.9	1.5	14.9		0.9	8.2
6	0.0	4.9	1.5	0.7	//	0.0	9.7
7	0.0	0.0	0.0	-0.4	/ /	0.0	0.0
8	0.0	4.9	2.0	1.3	/ /	0.0	9.0
9	3.3	1	3.2	26.6		12.0	18.7
10	1.7	1 /	2.5	/		12.0	/
11	1.7	1 /1	3.1	/ \|		12.0	/
12	1.7	1 1	2.8			2.4	/
13	0.0	1 /	5.2			2.4
14	0.0	1 1	4.4	-/		2.4
15	0.0	1 1	4.4	1 1		6.0	/
16	4.3	+	5.4	/1	/	12.1	/
17	0.1	+	2.6		L		/
18	11.5		12.1	Din No.	10201	Din No.	10204
19	6.0		1.4		0.6	PIN NO.
20	0.0		1.1		0.0	33	7.0
21	0.0			2	0.0	34	3.1
22	0.0				0.0	30	0.9
23	0.0			4	0.0	30	1.0
24	0.0			6	0.0	31	0.2
25	0.0				12.1	30	/.1
26	3.8			1 Q	3.3 6.6	39	2.2
27	4.7				0.0	40	9.1
28	2.8				0.0	41	3.1
29	2.8			11	50	42	3.1
30	0.0				5.9	40	5.1
31	2.0				5.2	44	5.U
32	2.2			1/		40	D.1
33	5.0			15	1.0	40	J.1 71
34	0.0			10	10.0	4/	/.1
35	4.1			17	25	40	3.2
36	4.4			18	3.5
37	0.0			10	4.5	50	0.0
38	0.0			20	6.0		1.3
39	4.9			20	0.0	52	0.0
40	4.9			21	0.1		0.0
41	4.9		1	22	11.0		0.0
42	4.9			20	5.3	55	0.1
				24	5.9	00	3.2
				20	4.9	5/	6.0
nput: PAL	Color Bar Sig	nal (with 1KHz A	Audio Signal)	20	3.3	58	4.8
Receiving (	Ch.: E2 ch (4/	8.25MHz)				59	3.1
reset Mode: Press Picture Select button on the remote			20	3.3	60	6.1
control unit.	then press th	he number "1" bi	itton	29	0.7	61	12.1
,,	Dright			30	8.3	62	6.1
	Bright	iess Center			6.4	63	12.1
	Color-	Center		1 32 '	63 I	64	i 81

VOLTAGE CHART

Brightness--- Center Color--- Center Contrast--- Approx 70%

8.1

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Pin No.	E	С	В
Q1	0.0	2.9	0.6
Q2	12.0	0.4	11.2
Q3	12.0	0.0	12.0
Q4	12.0	11.9	11.3
Q101	4.9	9.2	5.6
Q102	5.6	5.6	4.9
Q103	0.0	4.1	0.0
Q104	27.3	9.2	26.8
Q105	0.0	26.8	0.0
Q121	0.0	4.7	0.0
Q122	0.0	3.8	0.1
Q123	0.0	4.4	0.1
Q125	0.0	0.7	0.0
Q201	0.8	9.5	1.6
Q281	0.0	4.3	0.0
Q301	0.0	12.1	0.1
Q381	0.0	2.2	0.0
Q391	0.0	0.2	0.7
Q393	5.1	0.0	4.5
Q394	5.1	0.0	6.0
Q395	0.0	6.2	0.0
Q396	0.0	5.3	0.0
Q397	0.0	0.0	0.0
Q451	3.3	116.2	3.6
Q452	3.3	111.2	3.6
Q453	3.3	111.3	3.6
Q551	0.0	73.2	0.4
Q552	-0.2	124.0	0.0
Q601	1.0	_	0.0
Q603	0.0	1.1	-10.0
Q604	1.0	0.0	0.4
Q621	0.0	47.5	7.3
Q622	3.2	112	0.1
Q623	0.0	0.1	0.6
Q624	0.0	0.3	0.8
Q625	12.7	14.3	12.1
Q702	2.4	12.1	3.0
Q703	1.8	12.1	2.4
Q704	0.0	12.1	0.0
Q705	0.0	12.1	0.0
Q721	0.0	3.0	2.4
Q801	0.0	4.4	0.4
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