Tandy 1400LT Service Manual page 115

@ Memory Check
YES
0-3FFFFH
COOOH-FBFFFH
Check i f c o n n e c t o r
i s l o o s e ( C N 1 4 )
Check GATE2
mm,
m, c?xZ,
rn)
Check t h e power s u p p l y
v o l t a g e a t RAM (t5V)
I
Check Pin4:RAS a n d
P i n l 7 :C AS
a t
RAM
I
Check P i n 2 5 o f IC18
( f o r RAM r e f r e s h ) 4 b a b o u t l 5 p s e c
DACKO
s i g n a l
m
[ C h e c k , I C 1 8
1
Check P i n 1 3 o f
rn
I C 2 1 , 5 3
o u t 1 s i g n a l + ,
( f o r RAM r e f r e s h ) 1 5 p s e c
5-6