Sharp LC-20SH4U

LC-20SH4U
32
TROUBLE SHOOTING TABLE
Check the secondary
load of T7001.
Is pin (10) of IC1203 at
"H"?
Check the load of
IC1203 and its
peripheral circuits.
Is the primary
oscillation wave of
T7001 as specified?
Are the secondary
outputs of T7001 +5V, -
12V, +35V and +9V?
Is there DC 12V input at
T7701 and pin (8) of
IC7301?
Is the output voltage of
IC1203 as specified?
Check the load of IC701
thru IC703.
Check T7701, IC7701
and their peripheral
circuits.
Check T7701, IC7701
and their peripheral
circuits.
Is there DC 18V input at
F6700 thru F6704?
Check the primary side
of T7001, IC7301 and
its peripheral circuits.
Disconnect F6700 thru
F6704. Is the load short-
circuited?
Check the related
line, IC1004 and its
peripheral circuits.
Is pin (187) of IC1004
at "H" or pulse?
Check the inverter unit
and fluorescent lamp,
and replace as required.
Check the primary side
of T7001, Q3305 and
its peripheral circuits.
Check the connections
between pin (4) of
SC2003 and pin (2) of
SC4201.
No video and audio output (no power) No fluorescent lamp light-up
No No
No
No
No
No
No
No
No
Are F6700 thru F6704 as
specified?
Replace F6700 thru
F6704.
Yes
Yes
Yes
Yes
Yes
Yes Yes
Yes Yes
Check the microprocessor's adjustment process menu for wrong settings.