Specifications

REV.-A
Table 5-5. Repair of Power Supply Board (Cont.)
Symptom Conditon Cause Checkpoint Solution
The printer
+5V line is
+35V line
Check the
+35V line.
does not
op- dead. is dead.
crate at all.
IC51 is
Check the oscillation waveform and switching
Replace
dead.
waveform of IC51. IC51 .
+
1 f
T/ A
.
/
/
/ –
{
P
4ttt-
+t+t
3
2V
*
20 $s
Oscillation Waveform (IC51, pin 5)
I
\
I
-
“d
-
!’-
i+l+
* ++H-1-P -tttl-
!
$
1
1
mk’
*
I
Switching Waveform (IC51, pin 8)
Q51 or Q52
Replace
is dead.
Q51 or
Q52.
Q
-,
5-12