Chapter 11 Troubleshooting
Contents
1. 2 Agilent 10780C F Receiver Operating and Service Manual Agilent Part Number 10780 90028 Agilent E1708A Receiver Operating Manual Agilent Part Number E1708 90010 Agilent E1709A Receiver Operating Manual Agilent Part Number E1709 90006 wo See Chapter 8 Receivers of this manual for factory set value and range of 1070C F receiver sensitivity control For E1708A or E1709A see their respective manuals listed above NO Replace Auto Comp gt Block the beam so that it does not enter the receiver Does LED on receiver stay lit NO Measure voltage at receiver s test point Is o voltage ok YES Measure beam strength at input to receiver signal ok Check reference signal at Auto Comp Board test point 30 See Note 1 Reference signal ok Is beam strength ok Problem exists elswhere in system See Note 3 YES Refer to Receiver Oper Serv Manual See Note 2 Check measurement electronics and system laser head NO Refer to Receiver Operating Service Manual Alignments and Adjustments paragraphs regarding chapter 4 Check the Receiver cable and cable to axis board Cables ok Replace cables S Refer to Receiver Oper Service Manual See Note 2 Figure 11 3 Agilent 10717A Wavelength Tracker troubleshooting tree 11 14 User s Manual WARNING Chapter 11 Troubleshooting Before and A2. the following procedureis recommended Use a soft camel hair lens brush or equivalent to remove dust from the optical surfaces Dampen a few lens cleaning tissues with electronics grade methanol shake off excessive methanol and wipe across the lens surface once Use a fresh tissue dampened with methanol for each wipe Allow the methanol to evaporate The ends of the Agilent 10780F Agilent E1708A or Agilent E1709A fiber optic cable may be cleaned with a clean lint free cloth Periodically you may wish to verify proper beam alignment Refer to Chapter 8 Receivers Chapter 4 System Installation and Alignment and Chapter 7 Measurement Optics in this manual for procedures 11 10 User s Manual Chapter 11 Troubleshooting Troubleshooting Information Check for beam alignment at receiver using target Is LED lit on receiver Check for measurement signal at Axis or Auto Comp Board WHT BLk Beam alignemt ok Re align NO optics Note 1 YES Check for 15 0 5V the Receiver cable Check the Receiver cable measurement electronics NO output Axis or Auto comp board output WHT GRA GRN Backplane connector and power supply YE S Measure voltage at receiver s test point Measurement signal ok Problem exists elsewhere in system Perform Receiver alignment Is and Gain Adjustment voltage procedure outlined ok in Chapter 8 of this manual
3. ESD follow the following precautions 1 Ensure that static sensitive devices or assemblies are serviced at static safe work stations providing the proper grounding for personnel e g table mat with wrist strap 2 Ensure that static sensitive devices or assemblies are stored in static shielding containers e g antistatic poly bags 3 Donot wear clothing subject to static charge build up such as wool or synthetic materials 4 Donot handle components or assemblies in carpeted areas Do not remove the component or assembly from its static protective container until you are ready to install it 5 Avoid touching component leads or assembly edge connectors with your fingers Required Test Equipment The equipment required to maintain the laser heads and receivers is listed in Table 11 2 Other equipment may be substituted if it meets or exceeds the critical specifications listed in the table Refer to the appropriate electronics manual for a list of test equipment required for electronics maintenance and the calibration of environmental sensors Agilent 10751C or Agilent 10751D Air Sensor and 10757D Agilent 10757E or Agilent 10757F Material Temperature Sensor 11 4 User s Manual Chapter 11 Troubleshooting Troubleshooting Information Table 11 2 Recommended test equipment Instrument Characteristics Model Number Required Laser Power Meter Range 1 microwatt to 1 milliwatt Coherent Inc Accuracy 10 Ult
4. Measure beam strength at input to receiver Problem with optical Is See Note 3 path attenuation or beam strength low output from ok laser head Refer to Reciever Oper Service Manual See Note 2 Notes Voltage levels differential square wave at doppler shifted frequency 100 kHz to 7 2 MHz 100 kHz to 15 5 MHz for E1709A a White cable WHT y 2 5V 5V Meas Freq j b Black cable BLK Pe 2 5V 5V Meas Freq i Agilent 10780C F Receiver Operating and Service Manual Agilent Part Number 10780 90028 N Agilent E1708A Receiver Operating Manual Agilent Part Number E1708 90010 Agilent E1709A Receiver Operating Manual Agilent Part Number E1709 90006 wo See Chapter 8 Receivers of this manual for factory set value and range of 1070C F receiver sensitivity control For E1708A or E1709A see their respective manuals listed above Block the beam so that it does not enter the receiver Does LED on receiver stay lit NO Refer to Receiver Service Manual Alignments and Adjustments paragraphs chapter 4 See Note 2 Check the Receiver cable and cable to axis board Cables ok Replace cables Refer to Receiver Oper Serv Manual See Note 2 Figure 11 2 Agilent Receiver troubleshooting tree User s Manual 11 11 NOTE Chapter 11 Troubleshooting Troubleshooting Information Agilent 5519A B Laser Head intern
5. Receiver This section is basically written for troubleshooting the Agilent 10780C F receiver but many of the same techniques can be used to troubleshoot the Agilent E1708A or E1709A receiver F or troubleshooting information specific to the Agilent E1708A or E1709A receiver see their respective operating manuals Allow thelaser head sufficient time to complete its tuning cycle prior to determining whether or not the Agilent 10780C Agilent 10780F Agilent E1708A or Agilent E1709A receiver is working properly When the Agilent 10780C F receiver photodetector receives an adequate laser beam signal the LED indicator illuminates located on the Receiver s top surface and the DC voltage at the external beam monitor test point is greater than 0 7 See the Alignment and Gain Adjustment Procedure in Chapter 8 Receivers of this manual for procedures to adjust this test point voltage The alignment and gain adjustment procedures for the Agilent E1708A or E1709A receiver can be found in their respective operating manuals If the MEASUREMENT SIGNAL ERROR indicator on the Agilent electronics illuminates the problem may be with one of the system s measurement axis receivers If a SYSTEM ERROR indicator illuminates and the system is equipped with a Wavelength Tracking Compensation system the problem could be with the wavelength tracker axis receiver or the overall alignment of the Wavelength Tracking Compensation system components B
6. used in the measurement path If this situation occurs refer to the receiver s operating and service manual The troubleshooting tree of Figure 11 2 will help you determine if the Agilent 10780C Receiver Agilent 10780F Remote Receiver is faulty Repair of the Agilent 10780C or Agilent 10780F is outlined in the Agilent 10780C F Operating and Service Manual Table 11 3 shows the Agilent 10780C F Receiver signal chart Table 11 3 Agilent 10780C or Agilent 10780F Receiver signal chart Receiver Input Signal Name Output MEAS MEAS 15V Return RET 15V Wire Color BLK MEAS FREQ WHT MEAS FREQ WHT GRA 15V RETURN WHT GRA GRN 15V NOTE A dash following a signal name indicates a negative true signal The receivers should be inspected at least twice a year depending on their operating environment Inspect as follows e VISUAL INSPECTION Inspect the unit for indication of mechanical and electrical defects Look for signs of overheating corrosion accumulations of dust oil loose electrical connections or User s Manual 11 9 CAUTION Chapter 11 Troubleshooting Troubleshooting Information broken parts Also check the Agilent 10780F Remote Receiver for loose fiber optic connections at both ends of the fiber e REPAIR AND CLEANING Repair any obvious defects and if necessary clean the unit with dry clean compressed air or a vacuum cleaner To avoid scratching the lens during cleaning
7. 11 Troubleshooting Chapter 11 Troubleshooting Introduction Introduction This chapter provides information to help you find defective components in an Agilent laser measurement system when a problem occurs It can help determine whether the problem source is in the system electronics environmental sensor laser head receiver or the optics Component level troubleshooting and calibration should be performed by Agilent Technologies technicians only However component level troubleshooting and calibration information is provided for selected assemblies This chapter is structured as indicated in Table 11 1 Table 11 1 Chapter content summary Instrument Type of Information Laser Heads System level troubleshooting for isolating the fault to the laser head Agilent 10780C 10780F System level troubleshooting for isolating the fault to a E1708A or E1709A receiver Agilent 107XX Optics System level troubleshooting for isolating the fault to the optical assemblies The Agilent 107XX optics are repairable only by Agilent Technologies Additional information is provided in the manuals that are supplied with each instrument 11 2 User s Manual WARNING Chapter 11 Troubleshooting Troubleshooting Assumptions Troubleshooting Assumptions The troubleshooting procedures assume that 1 The system controller is operating properly Before connecting the system controller to the Agilent electronics check the
8. Technologies where it will be evaluated for repair Follow the procedures outlined in Chapter 13 Packaging for Storage or Shipment of this manual for packaging methods and procedures User s Manual 11 13 Perform wavelength tracker Installation and Alignament Procedure outlined in subchapter 71 of this manual Check the Receiver cable measurement electronies Receiver connector Auto Comp Board backplane connector and power supply Perform Receiver alignment and Gain Adjustment Procedure outlined in Chapter 8 of the manual Problem with optical attenuation or low output from laser head Chapter 11 Troubleshooting Troubleshooting Information System error LED ON aR gt Check compensation mode control CMC 1 Check for alignment of beam through system optics wavelength tracker and receiver lit on wavelength tracker receiver Beam alignemt ok NO Auto Comp board LEDS off following power up sequence YES Check for 15 0 5V the Receiver cable Check measurement NO signal at Auto Comp Board test point 33 See Note 1 YES Measurement Notes Voltage levels differential square wave at doppler shifted frequency 100 kHz to 7 2 MHz 100 kHz to 15 5 MHz for E1709A a White cable WHT 2 5V 5V Meas Freq x b Black cable BLK tz 2 5V 5V Meas Freq
9. al receiver See the Agilent 5519A B Laser Head Service Manual for internal receiver troubleshooting information Optical device troubleshooting Problems with the optical devices are usually caused by their misalignment Refer to the alignment procedures in this manual for further information Air turbulence caused by ventilation equipment or temperature gradients near the laser beam path can also cause measurement problems If this is suspected shield the area around the laser beam and optical devices with cardboard tubing plastic sheet or other suitable material Some problems with sporadic counting and drift can be traced to air turbulence around the measurement path This should be considered as a possibility before troubleshooting other parts of the system If the problem is traced back to dirty optics refer to Procedures for Cleaning Measurement Optics in Chapter 10 Maintenance of this manual before you try to clean them Defective measurement optics should be returned to Agilent Technologies where they will be evaluated for repair F ollow the procedures outlined in Chapter 13 Packaging for Storage or Shipment of this manual for packaging methods and procedures Procedures for cleaning optics are given in Chapter 10 Maintenance of this manual Agilent 10717A Wavelength Tracker troubleshooting Troubleshooting the Agilent 10717A Wavelength Tracker involves proper interpretation of the Agilent las
10. controller by a Booting the unit up and verifying appropriate responses b Running your own known good programs and c Executing any controller diagnostics unique to your particular controller All system controls have been double checked to verify that they are in the proper positions This includes the correct setting of all circuit board address and test switches See Preliminary Checks or similar information in the troubleshooting chapter of your electronics manual All system cabling is configured correctly and that all cables are making proper electrical connection The system optics are clean Refer to Chapter 10 Maintenance in this manual Power to the system is removed before replacing any units or circuit boar ds You adhere to the precautions outlined in Electrostatic Discharge ESD section of this chapter The troubleshooting procedures cannot cover all possible malfunctions or combination of malfunctions However at the very minimum these procedures will direct you to the general area of the problem USE OF CONTROLS ADJ USTMENTS OR PROCEDURES OTHER THAN THOSE SPECIFIED HEREIN MAY RESULT IN HAZARDOUS LASER LIGHT EXPOSURE OR EXPOSURE TO HIGH VOLTAGES User s Manual 11 3 Chapter 11 Troubleshooting Electrostatic Discharge ESD Electrostatic Discharge ESD Electronic components and assemblies can be permanently damaged by electrostatic discharge To avoid damage caused by
11. er system electronics front panel annunciators system and board level self tests and knowing when the Wavelength Tracker requires realignment to the system optics The main system problems that could occur include e Misalignment of the wavelength tracker the receiver the system optics and system laser source Improper programming of system e Malfunction of the receiver e Malfunction of the Agilent system electronics for example the Agilent Automatic Compensation Board Troubleshooting trees Figures 11 2 and 11 3 respectively will help you determine if the Agilent receiver or the Agilent 10717A Wavelength Tracker is faulty 11 12 User s Manual Chapter 11 Troubleshooting Troubleshooting Information The front panel LEDs combined with the error messages listed in the appropriate electronics manuals provide assistance with both programming and hardware problems The SYSTEM ERROR LED illuminates when a problem occurs in the measurement or reference path of the Wavelength Tracker axis or when incorrect programming strings have been sent by the system controller By sending an error message query to the Agilent electronics via the system controller the system will respond indicating which board address is generating the error message and provide a brief description of the error The Agilent 10717A Wavelength Tracker is an optical device and is prealigned at the factory If found defective it should be returned to Agilent
12. fter Service Product Safety Check Before and After Service Product Safety Check The following safety checks must be performed after any troubleshooting and repair procedures have been completed to ensure the safe operation of the instrument RESISTANCE CHECKS DESCRIBED BELOW REQUIRE THAT THE POWER CORD BE CONNECTED TO THE INSTRUMENT AND THAT AC POWER BE DISCONNECTED BE SURE THAT THE POWER CORD IS NOT CONNECTED TO POWER BEFORE PERFORMING ANY SAFETY CHECKS 1 VISUAL INSPECTION Visually inspect the interior of the serviced instrument for signs of abnormal internally generated heat such as discolored printed circuit boards or components damaged insulation or evidence of arcing Determine and remedy the cause of any such condition 2 GROUND CONTINUITY TEST Plug the power cord into the Agilent electronics DO NOT CONNECT THE INSTRUMENT TO AC POWER Using a suitable onmmeter check the resistance from the enclosure chassis to the ground pin on the power cord The reading should be less than 1 ohm Flex the power cord while making this measurement to determine whether intermittent discontinuities exist The resistance check should be performed from the enclosure to the ground pin of the cord while flexing the interconnect cable 3 Check any indicated front or rear panel ground terminals using the above procedures 4 INSULATION RESISTANCE CHECK Tie the line and neutral pins of the power cable together Check resistance from the i
13. ima Labmaster or equivalent Digital Voltmeter Range 15V to 15V 0 01 Vdc Agilent 34401A NOTE Accurary of 0 01 Vdc required for voltage adjustments Oscilloscope Ability to display signals between dc Agilent 54624A and 100 MHz Clip on DC DC Current Range 1mA to 10A Agilent 34401A Milliammeter fullscale Accuracy 3 of full scale 0 15 mA Troubleshooting Information The possible system problems that can occur can be divided into the following areas Malfunction of the laser head Malfunction of one or more receivers Malfunction misalignment or improper application of the optical devices Malfunction of the system controller or its improper programming Malfunction of the Agilent system electronics If one of these areas is Suspect as the source of the trouble refer to the appropriate troubleshooting information and flowcharts provided in this section for that particular area User s Manual 11 5 Chapter 11 Troubleshooting Troubleshooting Information Laser Head troubleshooting Agilent 5517A B C D Laser Head Laser heads are listed herein the same order in which they are listed in Chapter 5 Laser Heads of this manual Laser head adjustment procedures are given in the laser head s own operating and service manual The following symptoms indicate problems with the Agilent 5517A Agilent 5517B Agilent 5517C or Agilent 5517D Laser Head If one or more of these sym
14. nstrument enclosure chassis to line and neutral with the LINE switch ON and the power source disconnected The minimum acceptable resistance is 2 Megohm Replace any component that results in a failure 5 POWER LINE MODULE CHECK Check line fuse and line voltage selector in the electronics rear panel power line module to verify that the correct fuse is installed and that the instrument is properly set for the AC source to be applied User s Manual 11 15 Chapter 11 Troubleshooting Before and After Service Product Safety Check 11 16 Product specifications and descriptions in this document subject to change without notice Copyright C 2002 Agilent Technologies Printed in U S A 07 02 This is a chapter from the manual titled Laser and Optics User s Manual For complete manual order Paper version p n 05517 90045 CD version p n 05517 90063 This chapter is p n 05517 90137 User s Manual
15. ptoms are observed use the Troubleshooting Tree Figure 11 1 to assist in determining if the laser head is actually at fault Detailed repair procedures are outlined in the laser head s operating and service manual e Nolaser light being emitted from the laser head exit port e Low power output from the laser head e LASER ON indicator not lit e READY indicator does not illuminate as expected Normally the indicator will start to blink on and off within three minutes of applying power to the laser head This indicates that the laser head is in the process of warming up When the Agilent 5517A Agilent 5517B Agilent 5517C or Agilent 5517D Laser Head is ready for use the indicator assumes a steady on condition e Absence of reference signal or bad reference signal e Agilent 5517B Agilent 5517C or Agilent 5517D Laser Head s 15V POWER ON or 15V POWER ON indicator is not lit 11 6 User s Manual Chapter 11 Troubleshooting Troubleshooting Information Is red laser beam Check input power Is NO visible either LASER ON at the Laser Head Voltages ok continuous or LED lit cable connector g Pins K M T 15V 0 3V flashing Problem is not in the laser head See Note 1 Check the following 1 Laser Head cable 2 Measurement electron Reposition ics output to cable turret 3 Measurement electron ics power supply Is front turret in the correct po
16. sition Is Laser beam flashing 2 YES Indicates a problem with the internal Indicates a problem Indicates a problem circuitry of the Laser with the internal with the internal Head Refer to Laser circuitry of the Laser circuitry of the Laser Head Service Manual Head Refer to Laser Head Refer to Laser Head Service Manual Head Service Manual See Note 1 See Note 1 See Note 1 Indicates a problem NO with the internal gt circuitry of the Laser After warmup the Laser Head Ready LED i Head Refer to Laser remains on Head Service Manual Notes 1 Also check pin L gt 15V 0 3V although it See Note 2 does not affect LASER ON LED 2 Agilent 5517A Laser Head Operating and Service Manual Agilent Part Number 05517 90046 Agilent 5517B C D Laser Head Operating and Is laser power output System problem Service Manual Agilent Part Number 05517 90047 exists elsewnere low Indicates a problem with the internal circuitry of the Laser Head Refer to Laser Head Service Manual See Note 2 Figure 11 1 Agilent 5517A B C D Laser Head troubleshooting tree User s Manual 11 7 NOTE NOTE Chapter 11 Troubleshooting Troubleshooting Information Agilent 5519A B Laser Head See the Agilent 5519A B Laser Head Sevice Manual for laser head troubleshooting information Receiver troubleshooting Agilent 10780C 10780F E1708A E1709A
17. y sending an error message query to the Agilent electronics via the system controller the system will respond indicating which axis is generating the error message Improperly aligned optical devices in either a measurement or a wavelength tracking axis can also cause a receiver to appear bad Check for this by either placing the receiver directly in the laser beam path from the laser head or by reflecting the laser beam onto the receiver s photodetector using a retroreflector This isolates all other optical devices from the system Most systems contain more than one axis and consequently more than one receiver If trouble is suspected with one particular receiver exchange it with another receiver to verify 11 8 User s Manual Chapter 11 Troubleshooting Troubleshooting Information the suspected malfunction If you suspect problems with the alignment of a receiver refer to Chapter 8 Receivers and Chapter 7 Measurement Optics in this manual for the appropriate alignment procedures A loose or broken fiber optic connection at either the remote lens or electronics of the Agilent 10780F Remote Receiver Agilent E1708A or Agilent E1709A can also cause the receiver to appear bad The receiver LED indicator may remain on even if the beam between the interferometer and the retroreflector is blocked This can occur occasionally with correct optical alignment if the measurement path is very short and few optical devices are
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