Spectravideo SVI 318 Service – Technical Manual page 28

Tll OUB LE SB001'IRG CHAR T
SYMPTON
N o pow e r
N o s o un d or
p i c t u re
N o p i c t u re
N o f u nc t i on
N o p i c t u re or
sound
POS S I BL E CAUSE
Pow e r s w i tch not
t u rne d on
Pow e r c a b l e n o t
c o nne c t e d
Wrong channe l
TV
Loo s e v i d e o ca b l e
TV vo l umn and co l o u r
t oo l ow
No ma s t e r c l ock
+ 5V
+1 2 V
- 1 2V
-SV
RESET
No ma s t e r c l ock
I n t e rrupt
ROM c h ip se l e c t
Use r RAM ch ip se l ec t
Wrong TV chan ne l
Loo s e v i d e o ca b l e
VRAM ch ip se l e ct
VDP i n t e r r up t
3.13
REMEDY
T u rn on pow e r sw i tc h wh ich i s
on r i g h t -han d s i d e o f the
mac h i ne .
Be s u r e t he pow e r c ab l e i s
conne c t e d t o the
r e p l a c e t h e brown f u s e .
S e l e c t c o r r ec t
TV
Be s u re a l l v i d e o cab l e s a re
s e cu re l y fas t e ne d .
Ad j u s t the vo l umn con t r o l
TV
and c o l ou r l e ve l o f your TV .
U s e o s c i l l o s cope t o che c k IC23
pin 4 an d I C 3 6 P in 3 9 .
C8 and 7 8 05C p i n 2
C 1 1 4 and 7 8 1 2 C p i n 3
7 9 1 2 C p i n 3 o r 79L05 p in 2
7 9 L05 p i n 3 and C 8 5
IC3 7 p i n 2 6
IC36 p i n 3 9 , 3 8 and IC3 7 p in 6
I C 3 7 p i n 1 7 , 1 6 , 1 9 and 2 0
I C 3 6 p i n 1 6
I C 3 1 p i n 1 1 , 1 2
IC 1 - 8 and I C 1 7 , 18 , p in 3 ,
4 , 1 5
S e l e c t c o r r e c t TV channe l
Be s u re a l l v i d e o cab l e are
s e cure l y f a s t e ne d
I C 9 - 1 6 , p i n 3 , 4 , 1 5
IC36 , p i n 1 6
ompu t e r and
c
channe l .