HP 5501A Operating And Service Manual page 174

I.
+15VUNBAL Lights when f15V dc power is high by approximately one-volt or more; or when the
(LED Lamp)
-15V dc power input is low (i.e., less negative) by one-volt or more.
2. -15V UNBAL Lights when -15V dc power is high (i.e., more negative) by approximately one-volt
(LED Lamp)
or more; or when the +15V dc power input is low (i.e., less positive) by one-volt or
more.
3. +15V FUSE Lights when +15V dc fuse blows.
(LED Lamp)
4. -15V FUSE Lights when -15V dc fuse blows.
(LED Lamp)
5. POWER ON
Lights when external power has been applied to Laser Head.
(LED Lamp)
6. LASER CURRENT Lights to indicate Laser Tube current
is
not within appropriate operating limits.
(LED Lamp)
7. RETUNE FAILURE Lights to indicate the Laser Tube is not properly tuned or that retune cycle did not
(LED Lamp) retune the laser.
8. RETUNE Lights to indicate that retuning is required or that retune cycle is in progress. Light
(LED Lamp) should go out approximately 9 seconds after the RETUNE pushbutton is depressed. If
light remains on, a tuning fault is indicated.
9.
RETUNE Manually activates Retune sequence.
(Pushbutton)
10. REFERENCE SIGNAL Allows the reference signals (REF and
REF)
and +15V power to be interconnected to
(Connector, Jl) other system components.
11. POWER Provides connection point for external power supply input.
(Connector, 12)
12. DIAGNOSTIC Allows monitoring of diagnostic signals and application of RETUNE command by
(Connector, J3) external equipment.
Figure 4-7. 5507A Laser Transducer Rear Panel Controls and Indicators