Sharp 20CT-250 Service Manual page 19

DESCRIPTION OF SCHEMATIC DIAGRAM
H SAFETY NOTES:
1. DISCONNECT THE AC PLUG FROM THE AC OUTLET BEFORE
REPLACING PARTS.
2. SEMICONDUCTOR HEAT SINKS SHOULD BE REGARDED AS
POTENTIAL SHOCK HAZARDS WHEN THE CHASSIS IS OPER-
ATING.
IMPORTANT SAFETY NOTICE:
PARTS MARKED WITH " å " (
) ARE IMPORTANT FOR
G
MAINTAINING THE SAFETY OF THE SET. BE SURE TO REPLACE
THESE PARTS WITH SPECIFIED ONES FOR MAINTAINING THE
SAFETY AND PERFORMANCE OF THE SET.
SERVICE PRECAUTION:
THE AREA ENCLOSED BY THIS LINE ( ) IS DIRECTLY
CONNECTED WITH AC MAINS VOLTAGE.
WHEN SERVICING THE AREA, CONNECT AN ISOLATING TRANS-
F FORMER BETWEEN TV RECEIVER AND AC LINE TO ELIMINATE
HAZARD OF ELECTRIC SHOCK.
WAVEFORMS
E
1 2.0 Vp-p (H) 2 1.3 Vp-p (H) 3 1.5 Vp-p (H)
D
C
6 3.0 Vp-p (H) 7 80 Vp-p (H) 8 80 Vp-p (H)
B
11 1.8 Vp-p (V) 12 0.8 Vp-p (H) 13 9.2 Vp-p (H)
A
16 145 Vp-p (H) 17 1000 Vp-p (H) 18 150 Vp-p (H)
1 2 3
20CT-250
NOTES:
1. The unit of resistance "ohm" is omitted.
(K = 1000 ohms, M = Meg ohm).
2. All resistors are 1/8 watt, unless otherwise noted.
3. All capacitors are µ F, unless otherwise noted. (P = µµ F).
4. All capacitors are 50V, unless otherwise noted.
VOLTAGE MEASUREMENT CONDITIONS:
1. Voltage in parenthesis measured with no Signal.
2. Voltages without parenthesis measured with 3mV B & W or
Colour-Signal.
3. All the voltages in each point are measured with VTVM.
WAVEFORM MEASUREMENT CONDITIONS:
1. Colour bar generator signal of 1.5V peak to peak applied at
Base of Video Buffer Amp. Q202.
2. Approximately 4.0 V AGC bias.
4 3.0 Vp-p (H) 5 3.0 Vp-p (H)
9 80 Vp-p (H) 10 5.7 Vp-p (H)
14 1.8 Vp-p (V) 15 55 Vp-p (V)
19 520 Vp-p (H)
4 5
19
20CT-250
Ë Ë Ë Ë Ë Tuner
NOTE: The parts here shown are supplied as an assembly but not independently.
H
G
F
E
Ë Ë Ë Ë Ë Infrared Remote Control Unit
NOTE: The parts here shown are supplied as an assembly but not independently.
D
C
B
A
6 7 1 8 2
å å å RTUNQ0004KJZZ å å
RRMCG0018PESA
9 3 10 4 11 5
20
12 6