Check
7,
CPU
P
ower
LED
Lights?
1.
Turn
on
the
4339B .
2.
Check
if
the
LED
\+5V"
of
DS1
on
the
A2
CPU
Board
Assembly
lights
.
Refer
to
Figure
4-10
for
DS1
location.
3.
If
the
LED
lights
,
proceed
to
\Check
8,
Any
Error
Code
on
LED?",
otherwise
proceed
to
\Check
9,
CPU
Fuse
High
Lead
V
oltage
".
Check
8,
Any
Error
Code
on
LED?
1.
Turn
o
the
4339B .
2.
Turn
on
the
4339B
while
watching
the
LEDs
on
the
A2
CPU
Board
Assembly
.
3.
Check
if
the
LEDs
light
as
the
sequence
shown
in
Figure
4-10.
4.
If
LEDs
light
as
the
sequence
,
replace
the
LCD
Assembly
,
otherwise
(possibly
\HAL
T"
doesn't
light
or
\BERR"
lights)
replace
the
A2
CPU
Board
Assembly
.
Note
When
replacing
the
A2
CPU
Board
Assembly
,
refer
to
\Replacing
the
A2
CPU
Board
Assembly"
in
Chapter
3
for
handling
the
ROM
and
EEPROM
on
the
A2
Assembly
.
Figure
4-10.
CPU
Board
Assembly
LED
Light
Sequence
4-14
T
roubleshooting
