Sharp PG-A20X (serv.man22) Service Manual ▷ View online
33
PG-A20X
YES
YES
YES
YES
YES
NO
Checking the
microprocessor
peripherals
Is a voltage of about 3.3V
DC applied to pins (3) and
(5) of IC1703?
DC applied to pins (3) and
(5) of IC1703?
Check IC1703 and its
peripheral circuits, or IC1702
and its peripheral circuits.
peripheral circuits, or IC1702
and its peripheral circuits.
Is the lamp access lid
open? Is the P2006 (LF)
tight in the socket?
open? Is the P2006 (LF)
tight in the socket?
Check IC2002 and its
peripheral circuits.
peripheral circuits.
Check IC8202, IC8203,
IC2601 and their
peripheral circuits.
IC2601 and their
peripheral circuits.
Check IC1704 and its
peripheral circuits.
peripheral circuits.
NO
Is about DC 2.5V applied
between pins (5) and (8) of
IC1704?
between pins (5) and (8) of
IC1704?
NO
Check IC8009 and its
peripheral circuits.
peripheral circuits.
NO
See if the fan is running as
specified. Or check IC8003
and its peripheral circuits.
specified. Or check IC8003
and its peripheral circuits.
NO
Is about DC 2.5V applied
between pins (4) and (3) of
IC8009?
between pins (4) and (3) of
IC8009?
Is there about DC3V
applied at pin (21) of
IC2002? Do the D0 thru D7
signals appear as pulse
signals on the oscilloscope
screen?
applied at pin (21) of
IC2002? Do the D0 thru D7
signals appear as pulse
signals on the oscilloscope
screen?
Fully close the lamp access
lid. Or insert the P2006 (LF)
tightly in the socket.
lid. Or insert the P2006 (LF)
tightly in the socket.
YES
Check IC8010, IC8011 and
their peripheral circuits.
their peripheral circuits.
NO
Is there 133-MHz clock
output at pin (6) of IC8010?
Is there 75-MHz clock
output at pin (6) of IC8011?
output at pin (6) of IC8010?
Is there 75-MHz clock
output at pin (6) of IC8011?
34
PG-A20X
YES
YES
YES
YES
Checking the lamp
light-up
Reconnect the CN751
and CN752 harnesses
tight enough. Or replace
these harnesses.
and CN752 harnesses
tight enough. Or replace
these harnesses.
Go to "Checking the
power unit".
power unit".
Replace the ballast unit.
NO
Go to "Checking the
microcomputer
peripherals".
microcomputer
peripherals".
NO
NO
Are DC350-400V voltages
applied between the pins
of CN703?
applied between the pins
of CN703?
NO
Is the lamp socket
disconnected?
disconnected?
Reconnect the lamp
socket tightly.
socket tightly.
Are the CN751 and
CN752 harnesses tight in
position in the power unit
and ballast unit as well?
Are these harnesses free
of damage?
CN752 harnesses tight in
position in the power unit
and ballast unit as well?
Are these harnesses free
of damage?
Are there 3V (High level)
and 1V applied at pins (1)
and (13), respectively, of
CN751 in the power unit?
and 1V applied at pins (1)
and (13), respectively, of
CN751 in the power unit?
NO
Checking the RGB
sync
Check IC6001 and its
peripheral circuits.
peripheral circuits.
NO
YES
Are there signal inputted
into pins (30),
(31) of IC6004?
into pins (30),
(31) of IC6004?
Are there signal inputted
into pins (2)
of IC5002, IC5015?
into pins (2)
of IC5002, IC5015?
Check RGB terminal and
its peripheral circuits
its peripheral circuits
35
PG-A20X
YES
YES
NO
YES
YES
NO
YES
YES
NO
Checking the RGB signal
Are their RIN2-RIN9,
GIN2-GIN9, BIN2-BIN9
signals inputted into
IC2601?
GIN2-GIN9, BIN2-BIN9
signals inputted into
IC2601?
Check IC8003 and its
peripheral circuits.
peripheral circuits.
Are the RGB signals
outputted from
pin (9), (7) and (4) of
IC3104? gradation signals?
outputted from
pin (9), (7) and (4) of
IC3104? gradation signals?
Check IC3104 and its
peripheral circuits.
peripheral circuits.
NO
Are their signals inputted
into pins(37)-(46) of IC1101,
IC1201 and IC1301?
into pins(37)-(46) of IC1101,
IC1201 and IC1301?
Check IC2601 and its
peripheral circuits.
peripheral circuits.
NO
Are there input signals at
pins (2) and (31) of
SC1101, SC1201 and
SC1301?
pins (2) and (31) of
SC1101, SC1201 and
SC1301?
Check IC1103 and its
peripheral circuits.
peripheral circuits.
Are there input signals at
pins (3) of SC1101 and
SC1301 and pin
(30) of SC1201?
pins (3) of SC1101 and
SC1301 and pin
(30) of SC1201?
Check IC1101, IC1201,
IC1301 and their
peripheral circuits.
IC1301 and their
peripheral circuits.
NO
Check the connection
of LCD panels.
of LCD panels.
And when video signal and
OSD are also not
disaplayed, replace the
LCD panels.
OSD are also not
disaplayed, replace the
LCD panels.
Are their signals inputted
into pins (5)-(10) of
SC1101, SC1301 and into
pins (23)-(28) of SC1201?
into pins (5)-(10) of
SC1101, SC1301 and into
pins (23)-(28) of SC1201?
Check IC1101, IC1201,
IC1301 and their peripheral
circuits.
IC1301 and their peripheral
circuits.
36
PG-A20X
YES
NO
No colour or unusual
tone(NTSC, PAL)
Are there RGB outputs at
pins (23)(R-Y), (22)(B-Y) of
IC3105?
pins (23)(R-Y), (22)(B-Y) of
IC3105?
Check C3126 and C3124.
Check IC3105 and its
peripheral circuits.
peripheral circuits.
YES
NO
No or unusual Y signal
Are there RGB outputs at
pins (21)(Y) of IC3105?
pins (21)(Y) of IC3105?
Check C3121.
Check IC3506 and its
peripheral circuits.
peripheral circuits.
YES
NO
Checking IC3102 (RGB
signal output circuit)
Are there signal outputs at
pins (66)(R-Y), (68)(B-Y),
(69)(Y) of IC3102 ?
pins (66)(R-Y), (68)(B-Y),
(69)(Y) of IC3102 ?
Go to "No colour or unusual
tone", "No Y signal" or "Out
of sync"
tone", "No Y signal" or "Out
of sync"
YES
NO
Are there RGB outputs
waveforms at pins(35),
(37) and (39) of IC3102 ?
waveforms at pins(35),
(37) and (39) of IC3102 ?
Check the data transfer and
other performance at pins
(55) and (56) of IC3102.
other performance at pins
(55) and (56) of IC3102.
NO
Are there output
waveforms at the emitters
of Q3110, Q3111 and
Q3112?
waveforms at the emitters
of Q3110, Q3111 and
Q3112?
Check Q3110 thru Q3112
and their peripheral circuits.
and their peripheral circuits.
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