Specifications
•
•
•
•
SYMPTOM SUSPECT
REMEDY
No
sound (picture and
Sound
IC
(UG), U3,
or
U9
is
Scope
for
audio
signal
at
pin 4
of
UG
video OK).
defective.
during Audio Test
on
Test Cartridge.
(continued)
If
no
Audio, replace
UG,
U9,
then
U3.
If
signal
at
pin 4
of
U6
OK,
but
no
signal
at
pin 9
of
U9, replace US.
A F
Modulator
is
defective.
First check the audio input lead of the
modulator for signal.
If
signal
is
pres-
ent, connect a known-good modulator
in
parallel wi
th
the modulator. Connect
the
RF cable
to
the
known-good
modu
·
lator and
touch
the
two
modulator cases
together.
Run
the Sound Test on the
Test Cartridge.
If
sound
is
OK
, replace
the
modulator.
Solder
bridges
or
foreign
material
Remove solder bridges
or
foreign
causing shorts.
material.
Hand Controller The Hand
Controller
is
defective.
Plug in a
known-good
Hand
Controller
malfunctions.
and
perform
the
Hand
Controller
Test.
UG
or
U3
is
defective.
Replace U6,
then
U3.
The
9 pin
connector
on
the
Logic Board
Check the 9 pin
connector
and
assO
-
for the Hand Controllers
is
defective.
ciated traces
on
the Logic Board.
,
Other
les
are
defective.
Replace, in the following order :
U4 ,
U2,
Ul,
U12,
and
U13.
The picture
suddenly
goes The test cartridge
is
defective.
Try another cartridge.
Also
check (he
blank duri
ng
the diagnostic
Master
Component
cartridge slot.
test.
One or more
ICs
are defective. Replace.
in
the following order :
Ul
,
•
U2.
and
U4
.
The reset
button
is
defective.
Check the reset
bunon.
Crystal X 1
is
defective.
GENTLY
tap
the
crystal
and
observe
the picture.
Foreign material
is
causing an
Inspect
the
Logic Board
for
foreign
intermittent short. material.
.
Picture action "freeze-up
."
One or more
les
are
defective. Replace, in the following order: U I ,
U4,
U2,
and
U3 .
The Test Cartridge
is
defective.
Try another cartridge.
The
Master
Component
cartridge
socket
(nspect
the
cartridge
socket
for
bent
is
defective. pins, foreign materials, etc.
Chann_1 Select switch does
The
switch
i.
defective. Replace
the
switch.
not operate correctly.
-
Th_
modulator
is
defective. Connect a known-good modulator
in
parallel
with
the
modulator.
Connect
the
RF cable
to
the
known-good
.
modulator and
touch
the
two
cases
together
.
Switch
the
Channel
Sel.ct
.
If
the
channel
now
changes, replace
the
modulator
.
-16-