Agilent Technologies 5517B Operation And Service Manual page 82

WARNING
WITH THE HP5517B/C/D COVERS REMOVED, VOLTAGES OF UP TO 12
KV WILL BE PRESENT AT THE OUTPUT OF THE HIGH VOLTAGE
POWER SUPPLY ASSEMBLY A2.
a. Apply power to the HP 5517B/C/D.
b. Wait until rear panel LEDs finish sequencing (see Table 3-1). The LEDs should reflect the following
status.
+15V POWER ON ..................................................................... ON
-15V POWER ON ...................................................................... ON
READY ...................................................................................... ON
LASER ON ................................................................................ ON
c. If laser light is not emitted from the laser head, check that the exit aperture shutter is open. Otherwise, see
High Voltage Power Supply Troubleshooting in paragraph 8-88). Within 10 minutes of turn-on, the
HP5517B/OD's READY LED indicator should turn on continuously, and the REFerence frequency signal
should have been enabled and applied to the rear panel connector.
Otherwise proceed with step d of this procedure. If the failure mode occurs after the 5517B/C/D has reached
the optical tuning mode (normal operation), skip steps d through k of this procedure. Steps d through k
address failures that prevent the laser head from reaching stable tuning.
d. Disconnect power and remove the covers of the HP5517B/G/D. Verify that all boards are seated correctly and
all test jumpers on the A3 board are in the left-most position (NRM).
e. Connect power. Check the following voltages. If any are incorrect, see Power Supply Troubleshooting in A3
Troubleshooting Procedures (paragraph 8-149) or see A1 Connector Board Troubleshooting Procedures
(paragraph 8-83):
• A3TP8: +14.7 V to+15.3 V
• A3TP9 (labeled "+5"): +4.75 V to +5.25 V
• A3TP10 (labeled "-15"): -14.7 V to -1 5.3 V
f. Turn the power off for a few seconds, then back on. Observe READY LED on the HP 5517B/C/D. Find the
READY LED description in steps g through j that matches your observation and follow that step.
g. READY LED (green) takes longer than 6 minutes to start to blink. Either the digital section is not working
or the heater is not being heated properly. Check the following procedures:
• A3 Digital Section
• A3 Power Amplifier
• A3 Warm-Up Error Amplifier
• A3 Subtracting Sample and Hold
h. READY LED (green) blinks within 6 minutes, blinks for less than approximately 150 seconds, goes off, then
repeats this action. This indicates that the warm-up mode feedback is not properly controlling the heater
voltage. Check the following procedures:
• A3 Power Amplifier
• A3 Warm-Up Error Amplifier
• A3 Digital Section
• A3 Subtracting Sample and Hold
i. READY LED (green) blinks within 6 minutes, blinks for less than approximately 150 seconds, comes on for
one second (twice as long as when it is blinking) then goes off briefly. This action is then repeated. Either the
optical mode feedback is not working or the reference receiver is defective. See Quick Tuning Checkout
Procedure, paragraph 8-67, and Reference Receiver Troubleshooting, paragraph 8-150.
j. READY LED (green) blinks within 5 or 10 seconds, comes on for a few minutes after approximately 3
minutes, then starts blinking again. Check A3 Power Amplifier section; especially A3Q3 and A1Q5.
k. Any other READY LED (green) observation indicates a defective digital section. See A3 Digital
Troubleshooting, paragraph 8-137.
l. If a REFerence frequency signal error is indicated after the laser head has successfully reached normal
operation (READY LED is on continuously and REFerence frequency signal is being output) make the
following observation. Does the READY LED extinguish when the failure occurs? if so, the optical tuning
may be failing or the reference receiver may be resetting the state machine due to marginal signal strength.
Use the Laser Power Output Test (paragraph 4-11) as a check of the laser tube assembly and Quick Tuning