Tandy 1400LT Service Manual page 128

Check WRITE GATE/
s i g n a l ( P i n 4
of
IC56)
C h e c k IC54
a n d IC56
P e r f o r m
a
READ o p e r a t i o n .
I
Check P i n 2 4 of C N l O
{Read d a t a f r o m FDD)
1
Check t h e FDD
u n i t
a n d t h e c o n n e c t i o n
Check DRQ
s i g n a l
c a b l e .
, ( P i n 1 4 of IC54)
I
I s a h i g h s i g n a l f e d
t o 82C37 (IC18) RESET
When t h e
Main SW i s
s e t t o ON?
0
C he c k I C 1 0
a n d I C 2
I s a c l o c k s i g n a l f e d t o
CLK o f 82C37
P i n 1 2 of I C 1 8 . 4.77MHz
Check I C 2
5-19