TD-20/20 LUMINOMETER SERVICE MANUAL

Transcription

1 TD-20/20 LUMINOMETER SERVICE MANUAL Rev. 1.0 CONTENTS Page Section 1 INTRODUCTION 2 Section 2 PRELIMINARY CHECKS 3 Section 3 TROUBLESHOOTING GUIDE 5 A. Shutter: Mechanical & Electronic 5 B. Injector: Mechanical & Electronic 6 C. Abort Run 7 D. Low/High/Drifting Readings 8 E. Response (no change in LCD readings) 9 F. High Voltage Alarm (HV bad) 10 G. Power Alarm (Low Pwr) 11 H. Problem with Data Collection (RS-232) 12 I. Keypad 12 J. LCD Blank or Dark 13 K. LCD Flashing 13 L. Alarm Condition: General Diagnostic Checkpoints 14 M. Replacing the NVRAM or EPROM 15 Appendix 1 MAIN BOARD LAYOUT 18 Appendix 2 REPLACEMENT PARTS Rev. 1.0 Page 1

2 Section 1 INTRODUCTION This manual will help you troubleshoot and repair most of the common problems encountered with the TD- 20/20 Luminometer. The User's Manual that came with your instrument contains useful information about operational parameters, calibration, alarms, and diagnostics; please consult it if you have a problem at this level. Materials required: - Digital voltmeter; - Standard electronics tools. 1. It has been our experience that what might at first appear to be an electronic failure often turns out to be operator error, or a loose connector or other simple malfunction. We strongly suggest you check the simple and obvious things first. (See SECTION 2.) 2. SECTION 3 describes troubleshooting by looking at the symptoms, including cases where an alarm is triggered. Section 3L describes general diagnostic checkpoints in alarm conditions. 3. You will find the board layout for locating components and checkpoints in Appendix A parts list for ordering replacement parts can be found in Appendix Rev. 1.0 Page 2

3 Section 2 PRELIMINARY CHECKS Troubleshooting should be performed in this sequence: a. Check for SOFTWARE problems; i.e., make sure operational parameters are correctly set; make sure sensitivity has been set properly and that level is adequate; check for correct standards, etc., if applicable. b. Check for MECHANICAL problems; i.e. correctly installed sample adaptor; sample compartment lid closed; sample seated correctly in sample holder; injector operational; power supply securely attached, etc. c. Finally, perform electronic diagnostics as found in this Service Manual. If you experience an apparent instrument failure, follow the following steps in order before going on to SECTION Verify that the power source at your site is working and appropriate for your instrument, i.e., VAC. Check for blown fuses and check circuit breakers at your site. 2. Make sure the power supply is securely plugged into the socket on the back panel and that the instrument's power switch is ON. If the power plug into the unit is loose, then UNPLUG THE UNIT. Take a small screwdriver and insert it into the slot in the center pin of the power plug socket on the rear panel. Widen the gap so the plug holds more securely. To test, plug in the unit and turn power switch ON. Check the instrument's power supply; the green LED on the power supply should be on when connected to the power source. 3. UNPLUG THE INSTRUMENT FROM THE POWER SOURCE. Remove the instrument from the case: a. Open the sample compartment lid. Using a 3/32 Allen wrench, remove the 4 screws holding the lid on. Take off the sample compartment lid. Be careful not to damage the soft gasket underneath the lid it is important for proper light seal. b. Remove the 7 screws on the back panel. c. Remove the 10 screws from the bottom panel. d. Lift off the case. CAUTION! Take care not to damage the ribbon cable to the LCD/keypad when removing the case Rev. 1.0 Page 3

4 4. Visually and manually check for loose connectors. The latches on the ribbon cable connectors are secured as a precaution with RTV, but they have been known to pop open. Visually and manually check to see that wires are seated in their connectors. The connectors are secured as a precaution with RTV, but wires have been known to slip out. Visually and manually check for broken wires. 5. Visually and manually check for loose integrated circuits (IC). Are the IC's snugly pressed into the IC sockets? 6. Check for any moisture on the printed circuit boards (PCB's) or on the components. If you find moisture, use a fan to dry the PCB's. 7. Check for corrosion on the PCB's or on the components, including the back side of the PCB. If corrosion is found: a. INSTRUMENT MUST BE TURNED OFF!! b. Use a fine wire brush to remove corrosion. c. Use isopropyl alcohol to remove any residue. te that the areas underneath the components, the sockets and connectors, may be corroded if there is moisture. The chips on the LCD are especially susceptible to corrosion. If corrosion is extensive, or if the IC's or sockets are affected, it is probably best to replace the board. 8. Check for burned areas on the PCB's or on the components. If there are black areas (clearly burned) then components may have to be replaced and/or traces may have to be reconstructed with jumper wires. Return to the If damage is extensive, it is probably best to replace the board. 9. To retest, reassemble the instrument: a. Check the sample block at the right rear of the instrument to make sure the large o-ring in the groove on the top of the block has no nicks or tears and is properly seated. b. Carefully replace the case of the instrument, paying attention to the LCD/keypad ribbon cable. c. Loosely replace the 7 screws on the rear panel and the 10 screws on the bottom panel; tighten them after case is properly aligned. d. Replace the soft gasket on top of the case over the sample compartment opening; for proper light seal, make sure it is undamaged. e. Replace the lid on top of the gasket, aligning it with the screw holes. Replace and tighten the 4 screws using a 3/32 Allen wrench. 10. Plug the instrument in. Turn it on using the power switch on the rear panel. If the instrument still does not work properly, go on to SECTION Rev. 1.0 Page 4

5 Section 3 TROUBLESHOOTING GUIDE A. SHUTTER - MECHANICAL te that it is difficult to tell whether a shutter problem is mechanical or electronic, unless you can see or hear the shutter mechanism operating. Thus, if there is a shutter problem, you will probably need to check both. Symptom Shutter stops partially closed/open Ticking or scratching noise during operation Shutter does not open or close (stuck) Problem/Solution 1. Instrument powered off while shutter was in motion. To check; power instrument off/on. 2. Improper alignment; return to Shutter slightly bent; return to power or bad connection; return to SHUTTER - ELECTRONIC Shutter does not move when instrument turned off, then on. Check for mechanical operation as in table above. Does it seem OK? Visually check connector M1 (motor connector) on the Main Board. Make sure that it is firmly seated. Tug gently on wires to make sure none are loose. Any loose connections? If shutter itself is bent or misaligned, contact Fix connections/wires. Finished. Bad M1 connector or shutter driver circuitry. Contact Rev. 1.0 Page 5

6 B. INJECTOR - MECHANICAL Symptom Injector cycles but does not pump fluid Injector leaks fluid at plunger Motor makes noise during injection Injector 2 operates when injector 1 selected Valve retainer tightened with reagent clip bracket interfering; some thread stripping Motor/plunger motion shakes during operation Problem/Solution 1. Tubing fittings loose. Check for leaks; tighten connections. 2. Valves stuck shut or missing. Remove & inspect valves as described in Operating Manual. 3. Valve cover not tight. Check for leaks and tighten. 4. Supply or injector tubing or needle plugged. Clear all tubing; check/replace as required. 5. Bad motor to plunger connection; return to Seal not tight or defective seal; replace tighten seal. Motor mounting screws loose. Remove case and check mounting screws on aluminum standoff posts. Motor leads crossed. Remove case to access connectors JP9 and JP10; unplug them and reverse them. Adjust clip bracket position and retighten. Defective motor or bad motor to plunger connection; return to INJECTOR - ELECTRONIC Turn the instrument off before removing from case to check any connectors. * With instrument powered on. Injector(s) do not operate when <GO> pushed. Push <GO>* key. Listen for sound of injector motor. Can you hear motor operating? Check connectors JP9 and JP10 on the Main Board. Make sure that they are firmly seated. Tug gently on wires to make sure none are loose. Any loose connections? Problem is mechanical, with the injector assembly valves, fittings, tubing, etc. Carefully check (see table above) and fix problem. Fix connections/wires. Finished. Bad connectors or driver circuitry (U29 or U30). Contact Rev. 1.0 Page 6

7 C. ABORT RUN Instrument aborts run and reads >9999; and shutter keeps clicking. Remove sample and press <GO> key. Does it abort? Sample concentration too high for current sensitivity setting; lower instrument sensitivity or dilute sample. Light leak somewhere. Check lid light seal; check injector(s) tubing, fittings, valves, etc. for light leaks. Replace as necessary. If this does not correct the problem, return to Rev. 1.0 Page 7

8 D. LOW/HIGH/DRIFTING READINGS Symptom Low reading Problem/Solution 1. Sample not mixed completely; all sample not at the bottom of the tube 2. Using auto-injectors: some reagents can stick in injector pump and tubing, causing interference with chemiluminescent reactions. Clean injector system thoroughly with distilled water; flush and soak overnight with 10% bleach in methanol (1 part bleach, 9 parts distilled water, and 90 parts methanol) solution. Flush again with distilled water. If this does not work, then replace tubing, ferrules, and valves. 3. Using auto-injector: a. Out of reagent b. Bubbles in tubing/lines. Prime the injector (you must prime 4 times). NOTE: Injection volume (250 µl) of the prime is independent of the injection volume chosen because the full 250 µl is required for adequate priming. c. Misaligned needle, causing poor mixing. Check tip of injector needle; if it is bent or damaged, replace it. 4. If there is no auto injector, and sensitivity is OK, it is possible that there is a problem with the PMT, signal amplifier circuitry, bad connection from PMT to main board, or a bad shutter. Check sensitivity level and sample concentrations first, then contact the High reading 1. Light leak somewhere. Check: a. Lid closure and seals b. Sample compartment plug and injector properly set c. Injector tubing should be covered by at least 3 inches of opaque shrink wrap d. Opaque shrink wrap should be pushed right up to injector needle adaptor 2. White labels or lab tape used for sample identification can phosphor-esce. 3. Check for sample or reagent spills inside compartment or on window. High Blank and/or variable readings Instrument sensitivity may be set too high; set instrument sensitvity and set to 65-70%. Setting as high as 85% increases noise and may produce high Blank (up to 3.000) and/or high reading variance (>10% CV). Drifting reading Chemiluminescence is temperature sensitive. Warm up instrument for same amount of time before each use and keep ambient temperature constant. 2 hours is enough for instrument to completely equilibrate Rev. 1.0 Page 8

9 E. NO RESPONSE (NO CHANGE IN LCD READINGS) Readings on LCD do not change during integration (no response). Make sure the shutter mechanism is working. Open lid. Turn unit off, then on while watching shutter mechanism to make sure it moves. Open lid slightly to avoid too much light leak. Does it move? Check the Sen % (HV) reading on the Diagnostic Screen. Press <HOME> <8>. Does it = 0? Open lid slightly. Does unit "abort" and display >9999? Try setting instrument sensitivity using light standard. Does Sen % still = 0 Make sure that there is no jumper across pins on connector JP2 on the Main Board. Is there a jumper? Bad shutter mechanism. Contact Unplug the unit! Check connection JP5 on the main circuit board. Any loose connections? Remove jumper. HV should return to normal. Sample concentration too low for current sensitivity setting. Increase sensitivity. Fix loose connection. Do LCD readings respond? If yes, finished. Bad HV circuitry or problem with PMT signal; contact Rev. 1.0 Page 9

10 F. HIGH VOLTAGE ALARM (HV BAD) "HV Bad" alarm; Sen % = 0 Make sure that there is no jumper across pins on connector JP2 on the Main Board. Is there a jumper? With the power ON, check the voltage at JP2 on the Main Board. Is it >1.5V? Check pin 10 of connector JP5 on Main Board. Is it >1.2V? HV driver circuitry problem. Contact the Bad connection in preamplifier or problem with HV module or HV monitoring circuitry. Contact Remove jumper. HV should return to normal. Problem with Q1. Contact Rev. 1.0 Page 10

11 G. POWER ALARM (LOW PWR) "Low PWR" alarm Perform preliminary checks on power in Section 2, paragraphs 1 & 2. Does this correct the problem? Unplug the unit! Remove the cover and check all cable connections, wires, etc. for loose connections. Check for visible burn spots. Fix any loose connections, etc. Does this correct the problem? Finished. Finished. Power supply detection circuitry on main board is bad. Contact Turn power ON. Check JP8 on the Main Board, with a probe across the wires. Is it 12V +/- 5%? Loose connection somewhere, or bad power supply, or loose power plug; see 1 & 2, Section 2. Could be a bad power supply or a bad power switch. (Make sure you have checked the items in paragraphs 1 and 2 of Section 2.) To check switch, with power ON, check the voltage at the red connector (bottom) from the power switch on the rear panel. Is it 12V? With the power switch in the ON position, check the voltage at the top connector from the power switch on the rear panel. Is it 12V? Bad switch. Contact Manufacturer Rev. 1.0 Page 11

12 H. PROBLEM WITH DATA COLLECTION (RS-232) Problem with RS-232 serial data output. Try a new cable. Does this correct the problem? Unplug the unit! Remove the instrument from the case. Access the RS-232 port on the Main Board (P1). Plug the cable directly into this port, and turn on the instrument. Does this correct the problem? Bad connection between main PCB and RS-232 outlet. Return to Finished. Bad RS-232 circuitry on the main PCB. Contact I. KEYPAD Certain keys, or all keys on keypad do not work. Unplug the unit! Remove the instrument from the case and make sure the following are securely seated; 1.The cable connector from the back of the keypad to the LCD/keypad PCB; 2. the connector from the LCD/keypad PCB to the main PCB (both ends). With power ON, does this correct the problem? Bad keypad; cable; or main PCB. Contact Finished Rev. 1.0 Page 12

13 J. LCD BLANK OR DARK LCD blank or dark (Make sure power OK by looking for shutter movement when unit turned on; open lid slightly to avoid too much light leak). Turn the power OFF using the power switch on the rear panel. Wait a few seconds and turn the power ON. Does the LCD appear? Finished, Adjust contrast by pressing down and holding the Up Arrow (if screen blank) or the Down Arrow (if screen dark) on the keypad. Is the LCD now readable? Finished, Unplug the unit! Check both ends of the ribbon cable connections for the LCD to the Main board (JP1). Are connections loose? Bad cable, LCD, or microprocessor; contact Plug in connections securely. If reading on LCD appears, then finished. K. LCD "FLASHING" LCD flashing or blinking Turn unit OFF using the power switch on the rear panel. Wait a few seconds. Turn power ON. Does the flashing stop? Finished, Possible that the NVRAM IC or the microprocessor is bad. See Section M Rev. 1.0 Page 13

14 L. ALARM CONDITION: GENERAL DIAGNOSTIC CHECKPOINTS If there is an alarm condition, check the obvious things first (see Section 2). Then, you may want to check the voltages on jumper JP4 on the Main Board (power supply and signal information). To check these voltages: 1. Unplug the unit. 2. Remove the instrument from the case (see Section 2, #3). See Section 2, #9 for reassembly. 3. Plug in the unit and turn on the power. 4. Locate connector JP4 on the Main Board. With the front of the instrument closest to you, pins are numbered from front to back, starting with Pin 1. NOTE: In some cases the labeling of numbers on the connector itself are reversed (i.e., 10 = pin 1); the square pad is pin Connect the negative (-) lead of your voltmeter to the chassis; touch the positive (+) lead to the checkpoint. Check and record the voltages according to Table 1. Table 1. JP4 Diagnostic Checkpoints Description rmal Voltage (front to back) Pin 1-5 ± 0.2V Pin 7 5 ± 0.2 V Pin 8 15 ± 0.5V Pin 9-15 ± 0.5V Pin ± V Voltage Reading If voltages are not within normal range, return to If readings are not normal, it means: Pin 10: Problem with the 2 Volt Reference IC (U8); Pins 1, 8, & 9: Problem with DC to DC Convertor (U9); Pin 7: Problem with 5 Volt Voltage Regulator (U13) Rev. 1.0 Page 14

15 M. REPLACING THE NVRAM OR EPROM It is possible, after some years use, that a warning screen may come up concerning the start-up test and non-volatile data (NEW/BAD NVRAM). This indicates that the Luminometer internal computer battery for data storage may be low. The instrument will still operate, but when the battery fails, every time it is turned off it will not retain instrument parameters and previous calibration settings. (The current battery has a 10-year life specification.) This situation can be solved temporarily by leaving the instrument ON at all times, until the NVRAM module can be changed. If it is turned off, instrument parameters will have to be reset and the instrument recalibrated. On rare occasions, the ERPOM may be replaced in order to update the instrument to the latest software version. INSTALLING THE NVRAM MODULE Refer to the Main Board Diagram in Appendix 1 to locate the NVRAM module. DO NOT TOUCH THE NVRAM PINS - static electricity can damage the NVRAM! 1. UNPLUG THE INSTRUMENT!!! 2. Remove the instrument from the case a. Open the sample compartment lid and using a 3/32 Allen wrench, remove the 4 screws holding the lid on. Take off the sample compartment lid. Be careful not to damage the soft gasket underneath the lid necessary for proper light seal. b. Remove the 7 screws on the back panel. c. Remove the 10 screws from the bottom panel. d. Lift off the case. CAUTION! Take care not to damage the ribbon cable to the LCD/keypad when removing the case. 4. w with the front of the instrument toward you locate the NVRAM module on the Main Board (on your left toward the front edge of the board). 5. Take a small flathead screwdriver and GENTLY pry the NVRAM module from its socket. Pry up the left side slightly, then the right side, alternating sides until the pins are clear of the sockets. Set the module aside. 6. Take the new NVRAM module, which should be marked "MK48Z08B. Locate the notch on the NVRAM module. The NVRAM module must be installed in the correct orientation, with the notch to your right with the front of the instrument toward you. CAUTION! Incorrect installation will damage the NVRAM module. The Main Board and IC socket are marked with white lines that show the proper orientation: Line up this small box with the notch on the module 7. Install the new NVRAM Module into the empty socket. Examine the module before installing to make sure all pins are straight. Carefully line up the rows of pins with the rows of sockets. Then Rev. 1.0 Page 15

16 gently press the pins into the sockets. When you are sure all pins are properly seated, use the flat side of a screwdriver to press the module evenly all around, making sure it is in as far as it will go. 8. Make a visual check of the inside components to make sure no wiring is hung up and that everything appears to be secure. 9. Plug in the instrument and turn on the power. When the instrument is first powered up a New NVRAM screen will be displayed. Check for normal operation by paging through screens, etc. 10. Reinstall the instrument in the case: Use care when reinstalling the instrument in the case in poor performance! improper installation will result a. Check the sample block at the right rear of the instrument to make sure the large o-ring in the groove on the top of the block has no nicks or tears and is properly seated. b. Carefully replace the case of the instrument, paying attention to the LCD/keypad ribbon cable. c. Loosely replace the 7 screws on the rear panel and the 10 screws on the bottom panel; tighten them after case is properly aligned. d. Replace the soft gasket on top of the case over the sample compartment opening; for proper light seal, make sure it is undamaged. e. Replace the lid on top of the gasket, aligning it with the screw holes. Replace and tighten the 4 screws using a 3/32 Allen wrench. INSTALLING THE EPROM Refer to the Main Board Diagram in Appendix 1 to locate the EPROM module. DO NOT TOUCH THE EPROM PINS - static electricity can damage the EPROM! 1. UNPLUG THE INSTRUMENT!!! 2. Remove the instrument from the case: a. Open the sample compartment lid. Using a 3/32 Allen wrench, remove the 4 screws holding the lid on. Take off the sample compartment lid. Be careful not to damage the soft gasket underneath the lid necessary for proper light seal. b. Remove the 7 screws on the back panel. c. Remove the 10 screws from the bottom panel. d. Lift off the case. CAUTION! Take care not to damage the ribbon cable to the LCD/keypad when removing the case. 4. w with the front of the instrument toward you, locate the EPROM module on the Main Board (on your left toward the front edge of the board, just to the right of the NVRAM). 5. Take a small flathead screwdriver and GENTLY pry the module from its socket. Pry up the left side slightly, then the right side, alternating sides until the pins are clear of the sockets. Set the module aside Rev. 1.0 Page 16

17 6. Take the new EPROM module. Locate the notch on the module. The module must be installed in the correct orientation, with the notch to your right with the front of the instrument toward you. CAUTION! Incorrect installation will damage the module. The Main Board and IC socket are marked with white lines that show the proper orientation: 7. Install the new Module into the empty socket. Examine the module before installing to make sure all pins are straight. There are more sockets then there are pins, so the module should be installed with the pins on the un-notched end of the module inserted flush with the sockets on the side closest to the NVRAM. (This means that 2 sockets on each row will be empty on the right side of the module base.) Carefully line up the rows of pins with the rows of sockets. Gently press the pins into the sockets. When you are sure all pins are properly seated, use the flat side of a screwdriver to press the module evenly all around, making sure it is in as far as it will go. 8. Make a visual check of the inside components to make sure no wiring is hung up and that everything appears to be secure. 9. Plug in the instrument and turn on the power. The title screen will indicate a new software date/version. Check for normal operation by paging through screens, etc. 10. Reinstall the instrument in the case. Line up this small box with the notch on the module Use care when reinstalling the instrument in the case in poor performance! improper installation will result a. Check the sample block at the right rear of the instrument to make sure the large o-ring in the groove on the top of the block has no nicks or tears and is properly seated. b. Carefully replace the case of the instrument, paying attention to the LCD/keypad ribbon cable. c. Loosely replace the 7 screws on the rear panel and the 10 screws on the bottom panel; tighten them after case is properly aligned. d. Replace the soft gasket on top of the case over the sample compartment opening; for proper light seal, make sure it is undamaged. e. Replace the lid on top of the gasket, aligning it with the screw holes. Replace and tighten the 4 screws using a 3/32 Allen wrench Rev. 1.0 Page 17

18 Appendix 1 MAIN BOARD LAYOUT Rev. 1.0 Page 18

19 Appendix 2 REPLACEMENT PARTS Contact the manufacturer for prices and additional parts. Refer also to the TD-2020 Ordering Information Booklet for items such as injector tubing and valves, reagents, instrument power supply, etc. Part Description Part Number Main PCB Assembly Main Power Cable Assembly LCD Keypad Assembly RS-232 Cable Assembly NVRAM Module EPROM Module Contact the manufacturer for latest version Contact the manufacturer for latest version Rev. 1.0 Page 19