Sharp DV-5145, Service Manual

RF AGC cut-in adjustment: 

1. Receive 10 ch. signal.

2. Set the signal input level at 52   1 
3. Connect CR oscillator to TP202 across a capacitor of

10 

 This capacitor is to cut off DC supply.

To TP201

l 

Oscillation frequency: 1 

 sine wave

l 

Output voltage

: 0.1 vp-p

(when connected to TP202)

4. Adjust R225 so that 1 

 signal disappears from TV

screen.

5. Set the signal input level at 

 and check that

1 

 signal appears on TV screen.

If 1 

 signal does not appear, set the input signal

level at 52 

 again and follow the procedure in

step 4 again.

Sound detector coil adjustment: 

1. Connect signal generator’s output to TP301.

l 

Generator’s central frequency: 5.5 MHz

l 

Modulation: No modulation

l 

Generator output: 80 

 (terminated with 

2. Connect DC voltmeter to TP302.
3. Adjust sound volume to minimum and measure the

voltage then available at TP302; this voltage (about

 should be regarded as a reference voltage.

4. Adjust sound volume to maximum and turn the core

of T301 (sound detector coil) until DC voltmeter reads

the reference voltage obtained in step 3 above.

Horizontal 

 adjustment: R605

1. Receive monoscope pattern signal.
2. Short TP601 and TP602 (at both ends of 

3. Adjust R605 to obtain good horizontal sync on 

screen.

4. Remove the short-circuit between TP601 and TP602.

Sub-brightness adjustment: R415

1. Short TP401 and TP402.

2. Set each control as follows:

l 

Screen control: at MIN position

l 

G-bias control 

 at MIN position

l 

B-bias control 

 at MIN position

l 

R-bias control (R869): at MIN position

l 

G-drive control 

 at CENTER position

l 

B-drive control 

 at CENTER position

l 

Contrast control (R 1110) : at M IN position

l 

Brightness control 

 110): at CENTER position

l 

Picture control   1110) : at CENTER position

l 

Colour control 

 110) : at MIN position.

3. Receive monoscope pattern signal.
4. Connect oscilloscope to TP850 (with L2 connected to

ground)

5. Adjust 

 (sub-brightness control) so that the

output waveform on oscilloscope is at 15 Vp-p.

6. Remove the short-circuit between TP401 and 

Background adjustment:

 G-drive control, 

 G-bias control

 B-drive control, 

 B-bias control

Screen control, R869; R-bias control
1. Receive monoscope pattern signal.
2. Set each control as follows:

l 

Brightness control: at CENTER position

l 

Contrast control: at MIN position

l 

Screen control: at MIN position

l 

G-, B-drive controls: at CENTER position

l 

R-, G-, B-bias controls: at MIN position

3. Short 

 and TP402.

4. Turn screen control until horizontal raster slightly

appears on 

 screen.

5. One of the colours (R, G and B) appears first as

screen control is turned. So touching off the bias
control belonging to the first colour, adjust the other
controls as follows to make white the horizontal
raster.

First 

colour 

Bias controls to be next turned.

Red

Green 

R869,

Blue 

R869,

6. Turn screen control until the raster disappears and

stop it.

7. Remove the short-circuit between TP401 and TP402.
8. Set contrast control at MAX position.

10