Read Sharp LC-20B2EA Service Manual online
13
LC-20B2EA
TROUBLE SHOOTING TABLE
No picture and No sound
Check all the settings microprocessor's adjust process menu.
Do F1 and F2 function?
Are T3701's secondary
outputs, +31V, +22V, +9V,
+5V and -8V normal?
Remove F1 and F2 and
check the load side.
Is there short-circuiting?
Is there short-circuiting of
T3701 primary side periphery,
Q3700, Q3701 and S4701.
Replace F1 and F2.
Check S4701 and
connection cable.
Is T3701's primary oscillator
waveform normal?
Check T3701's secondary
load.
Yes
Yes
No
No
No
No
No
Yes
Check J3702 periahery and
connection cable.
Replace F6700~F6704.
Is the pin (34) of IC1201 in
the "H" state?
Is the output of Q3650 in the
"L
" state?
Yes
Yes
No
No
No
Yes
Yes
Check the OFL1 line, IC1201
and their peripheral parts.
Check the OFL line, Q3650
and their peripheral parts.
Check T6700~T6709,
Q6700~Q6714 and
connection cable.
Back light lamp failure to light up
Is the primary side of
T6700 ~T6709 periphery
short-circuiting?
Replace the back light lamp
with new one and check
again.
Click on the first or last page to see other LC-20B2EA service manuals if exist.