Laser Current Loop Failure Analysis - HP 5501A Operating And Service Manual

Model 5501A
Maintenance
Figure 4-2. Laser Current Loop Failure Analysis
4-6
A1 CONNECTOR BOARD ASSY
L
* - - - - - - - -
~ L A S E R
L A S E R
-
1
I
' Z D R J R U E S N T T
CURRENT
I
' @
T.P.
I
I
0
I I
I
I
I
I
LASER CURRENT
I
REGULATIOPI CIRCUITS
L
- - - - - - - - - -
J
CONTROL
A3 LASER TUBE ASSEMBLY
J
t l
1 4
CATHODE
v
ANODE
-
+15V
1
Q1
SERIES
i
A2 HIGH VOLTAGE
POWER SUPPLY
ASSEMBLY
REGULATOR
0
s 2
- -
SAFETY SWITCH
-15V - l S V
0
-
Items listed in order of most probable cause of failure:
@
a. Check -15V input.
b. Check Fuse F2.
c. Check that safety switch 52 is engaged and functioning correctly.
@
a. Check A2 High Voltage Power Supply.
b. If A2 i s replaced, perform laser current adjustment.
@ a. Check Q1 series regulator.
b. If replaced, perform laser current adjustment.
@ a. Check A1 connector board assembly.
b. If replaced, perform laser current adjustment.
@
a. Check A3 laser tube.
b. Perform laser current adjustment.
c. Perform reference threshold adjustment.