Sharp XV-ZW99U - Checking the B signal line of signal processing PWB

1
xv-zw99u
TROUBLE SHOOTING
TABLE
(Coutinued)
Checking the B signal line of signal processing PWB
I
Check pin (5) line of connector TN :
Do voltages at pins (7) (18) and (19)
of lC3502 change?
1 Yes
,
No 4” iC3502, IC2001 or nearby circuit in i
trouble
:
Is there signal input at pin (1) of
IC3512?
I Yes
No
t
1s there signal input at pin (66) of as
specified lC3504 ?
No ; lc3512 or nearby circuit in trouble
:
I Yes
thru (25) of IC4016?
Yes
Are there signals input at pins (128) No <
and (196) of lC3507?
Go to “Checking PLL-1 circuit” j
: ,, . . .
Yes
No ” Are there signals input at pins (198)
and (201) of lC3507?
_ Go to “Checking synchronization-l q :
Yes
Are there Bus signals input at pins
(157) (158) and (161) of lC3507?
Yes
No ;“’
7 IC2001 or nearby circuit in trouble j
:
No j.
Are there signals input at pins (a), (9) * lc3507t lc3508’ lc2”’ Or nearby :
(174) (175) (178) thru (180), (187)
circuit in trouble
(188) (193) thru (199) and (205) thru
1 (208)i1fl4008? 1
Go to “Checking MMC circuit ” j
Is there CLKR signal at pin (26) of
IC4006, Q4011, Q4012 or nearby :
circuit in trouble
32