Sharp PG-A20X (serv.man12) Service Manual ▷ View online
31
PG-A20X
TROUBLE SHOOTING TABLE
YES
YES
NO
Checking the basic
performance
Is the POWER LED on or
flickering in red or green?
flickering in red or green?
Go to "Checking the
power unit"
power unit"
Go to "Checking the lamp
light-up"
light-up"
NO
Is the set turned on by the
set’s or remote controller’s
power key?
set’s or remote controller’s
power key?
Go to "Checking the
microcomputer
peripherals".
microcomputer
peripherals".
NO
Go to "Checking the RGB
sync".
sync".
Go to "Checking the RGB
signal"
signal"
Go to "Checking the
video system".
video system".
End
NO
Is the cooling fan
running? Is the lamp on?
running? Is the lamp on?
Is the user menu
displayed?
displayed?
YES
YES
32
PG-A20X
YES
YES
YES
YES
NO
Checking the power unit
Are the connectors CN701,
CN702 and CN751
inserted completely?
CN702 and CN751
inserted completely?
Insert the connectors
CN701, CN702 and
CN751 tightly?
CN701, CN702 and
CN751 tightly?
Replace the bimetal
NO
Replace F701.
NO
Check Q702 for damage.
Replace as required.
Replace as required.
NO
Is the bimetal switch off?
Is there AC voltage (110-
240V) applied across
C701?
240V) applied across
C701?
Disconnect the CN751
connector. Is there 6V
output at pins (3) and (4)?
connector. Is there 6V
output at pins (3) and (4)?
Check the MAIN PWB for
short-circuit.
short-circuit.
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
Display