SONY FDL250T
Manual de Servicio

SECTION 2 DISASSEMBLY
2-1. CASE, A BOARD AND H BOARD REMOVAL 2-2. LCD CASE AND B BOARD REMOVAL [SETUP](A BOARD )

SECTION 3 CIRCUIT ADJUSTMENTS
1. Apply a DC voltage of 4.5V±0.1V to the J601 terminal (DC input jack) on the A board. 2. With S601 on the A board at UHF position, set the User Control RV-550(VOL) and RV-901(BRT) on the H board to their mechanical centers.

< A BOARD ALIGNMENT > 3-1.VIF.AFT ROUGH ALIGNMENT (T201, T202)
[SETUP] 1. Set S601 on the A board to VHF position. 2. Apply no signal to JL119 (RF). 3. Connect a 1 k� resistor between JL09 (+5.0V) and JL13 (RF AGC). 4. Apply a sweep signal across JL12 (IF) and JL14(IF GND). (Fig. 3-1) Note : Set the sweep signal for JL12 to -30±5dBm. Keep the distance to the ATT output JL12 as short as possible.

3-2.AFT FINE ADJUSTMENT (T201)
1. Connect a 1 kilohm resistor between JL09 (+5.0V) and JL13 (RF AGC). Note : Perform this adjustment as the last step in the process since drift may occur due to aging. 2. Switch the sweep signal to CW. fo= 45.75 MHz±5 kHz, -30±5dBm Apply the above signal between JL12 (IF) and JL14 (IF GND) and then make a fine adjustment of T201 so that the level between JL02 (AFT) and JL01 (D.GND) reaches2.2V±0.4VDC. 3. Remove the 1 kilohm resistor connected between JL09 (+5.0V) and JL13 (RF AGC).

< B BOARD ALIGNMENT >

- B board (Component side)

RV302

RV301

RV308

[+5.0V ALIGNMENT (RV600)](A BOARD )
2 Three screws 2 LCD case (upper)
1 Battery cover

RV306

(7-685-105-19)

4 B board

Using a digital voltmeter measuring the voltage between JL09 (+5.0V) and JL87 (A.GND). Adjust RV600 to obtain the value shown below.
LCD case (lower)

3-5.V COM ALIGNMENT (RV302, RV306)
1. Adjust BRT VR (RV901) to1.740±0.005VDC, between JL301(BRT) and JL307 (A.GND). 2. Observe the waveform across JL411 (V COM) and JL407(GND). 3. Adjust RV302 (COM AMP) and RV306 (V COM DC) so that the waveform resembles that in Fig. 3-5. Note : The voltage at pin 37 (COMMON AMP) of IC302 shall be a minimum of 1.8V.
5.0V±0.1Vp-p 0V -1.4V±0.1Vp-p

3 LCD holder

Standard Value = 4.55V± 0.02VDC S601 position = UHF position

3-3.RF. AGC ALIGNMENT (RV201)
0.01µF SWEEP MARKER GENERATOR fo=45.75MHz±5kHz

Battery case (lower)

[+30.0V CHECK](A BOARD )
3 A board 4 H board

Check the voltage across JL07 (+30.0V) and JL87 (A.GND) . Standard Value = 32.0V±2.0VDC

ATT
JL12 75� 6dB

1. Set S601 to VHF position and receive a VHF color bar signal issued from a signal generator. 2. Adjust RV201 and align the screen for the optimal point so that the snow noise disappears.

3-4.CHANNEL DiISPLAY POSITION ALIGNMENT (RV001, RV002, RV004)
1. Set S601 to VHF position, a potentiometer (47k�±15k�) across JL06(CS) and JL09 (+5.0 V) as shown in Fig. 2-6 and short the points JL04(CH CAL) and JL01 (D.GND). 2. Receive channel 2 and align the channel display positions with RV002(VP). 3. Receive channel 13 and align the display bar with RV004(VA). 4. Align while performing tracking to mutual interference in the above steps 2 and 3. 5. Receive channels 3 & 4 and confirm that the display bar is within the standards. 6. Set S601 to UHF. 7. Receive channel 14 and align the display position with RV001(UP). 8. Receive channel 69 and confirm that the display bar is within the standards. If not within standards, align with RV001 so it is within standards. Once again receive channel 14 and confirm that the display bar is within the standards. Note : Use caution since shifting channel 69 will also cause channel 14 to shift. 9. Remove the potentiometer (47k�+15k�) you connected beFig. 3-6

[+7.5V CHECK](A BOARD )
Check the voltage across JL08 (+7.5V) and JL87 (A.GND) .
1 Hinge collar

Fig. 3-1

Standard Value = 7.0V± 0.3VDC

5 Battery case (upper)

[-10.0V CHECK](A BOARD )
Check the voltage across JL10 (-10.0V) and JL87 (A.GND) . Standard Value = -9.5V± 0.6VDC

1. Connect an oscilloscope between JL86 (VIDEO) and JL87 (A.GND) and apply an external voltage (MGC) to JL26 to obtain a waveform as shown in Fig. 3-2 (make sure not to clip the extremely short portion).Adjust T202 so that the position at 45.75 MHz is the lowest point. Note : Align JL26 (MGC) external voltage for approximately a 1.0 Vp-p. Make sure that the JL26 (MGC) external voltage does not exceed 4.3VDC. 2. Remove the external voltage (MGC) from JL26. 3. Connect an oscilloscope between JL02 (AFT) and JL01 (D.GND) and make a rough adjustment of T201 so that waveform is close to zero at the 45.75 Mhz position. 4. Remove the 1 kilohm resistor connected between JL09 (+5.0V) and JL13 (RF AGC).

Fig. 3-5

3-6.CONTRAST ALIGNMENT (RV301)
1. Receive the stepped waveform signal in 10 steps. 2. Observe the waveform across JL421(VG) and JL407(GND). 3. Align RV301 (CONT) so that 100IRE section matches the standard below. (Fig. 3-6)
10thstep (101IRE)

2-3. SERVICE POSITION

- A board - (Component side)
B board
J601 EXT ANT

3.0V±0.1Vp-p

J601
RV002 RV004

A board CN401

RV600

RV001 RV201

RV003 T201 T202

3-7.COLOR PHASE (TINT) ALIGNMENT (RV-308)
1. Receive the color bar signal from the signal generator. 2. Observe the waveform across JL422(VB) and JL407(GND). 3. Adjust RV308 (TINT) so that the waveform level resembles that of Fig. 3-7.

CN301 AC power adaptor CN201 H board J101

J601 DC IN JACK

10Vp-p

tween JL06(CS) and JL09(+5.0V). Also remove the short you connected between points JL04 (CH CAL)and JL01(D.GND).
JL06 (CS) JL09(+5.0V)

45.75MHz

Display bar
15k� VR(47k�)

Align so the

portion is parallel and linear.

Channel No. 6
*Channel No. and display bar are to be in line.

Cord Antenna

0

Fig. 3-2

Fig. 3-4

Fig. 3-4 Fig. 3-7

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