Troubleshooting a K40 Laser Power Subsystem
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Symbol Key These symbols are used in this document to designate a functions as described below = the O path in a flow? = a connector to another flow Y = a YES path in a flow? = A test procedure used in a flow
Preparation: Make a safe environment When the beam is or may be present: Ensure all covers & interlocks are engaged Wear your laser eye protection Turn O the power to the machine Is the green LED on the LPS illuminated? ote: some LED s may be red. The LPS is not getting AC power or it has an internal failure A Y Proceed to B
Testing Methods Testing the AC Input: A Use this table and test method to test for the correct ACV AC AC AC from mains AC from mains Caution: Read HIGH VOLTAGE with DVM on AC voltage scale across these pins G Ground With DVM on volts scale read to ground 0vdc L- Laser cathode return DO OT MEASURE. Depends on country (120-220VAC) P or Q Is the proper AC voltage present? Y You said the green LED was not illuminated on the LPS. That got you here. The correct VAC is present at the LPS therefore something is internally wrong with your LPS. I Check: The wiring from the K40 main AC socket to the LPS AC connections The fuse located in the input plugs receptacle could be blown. Power at the wall plug could be wrong or missing. Shown is US power. Your plugs may be different.
Initial Tests: B When you push the Test button down on the LPS does the laser fire? Something is wrong with your LPS. I Y Insure all interlocks are closed Interlocks may be: Covers Water flow switch Over temp switch At the control panel Engage the Laser Switch When you push the Test Switch button on the control panel does the laser fire? Something is wrong with the control panel its wiring, the laser or the LPS D Y Your laser is MAUALLY operating properly. Test the programmatic operation of your machine. K
Connectors from right to left Troubleshooting white connector Control Panel s connection to the LPS D Do the connectors on your LPS look like this? Y Perform the tests in the table below Go to F Signal Function Test Procedure Correct Reading L 5V Laser fire from controller 5vdc to controller Touch this pin to ground and the laser will fire if the LASER SWITCH is on. With DVM on volts scale read to ground Laser fires 5vdc G Ground With DVM on volts scale read to ground 0VDC 24V 24vdc to controller With DVM on volts scale read to ground 24vdc 5V 5vdc to pot With DVM on volts scale read to ground 5vdc I Analog power With DVM on volts scale read to ground. Voltage varies as pot is turned 0-5vdc G Ground With DVM on volts scale read to ground. 0vdc K+ Laser Test Button Push & Hold Laser Test Button & measure with DVM on volts scale to ground. K- Laser Switch With switch On reads on volts scale with DVM to ground 0vdc 0vdc G Ground With DVM on volts scale read with to ground 0vdc P+ Laser On With Laser On switch O on volts scale with DVM read to ground Ovdc AC AC AC from mains AC from mains Caution: Read HIGH VOLTAGE with DVM on AC voltage scale across these pins G Ground With DVM on volts scale read to ground 0vdc L- Laser cathode return DO OT MEASURE. Depends on country (120-220VAC) H
Connectors from right to left Troubleshooting green connector control panel s connection to the LPS F Do the connectors on your LPS look like this? Y Perform the tests in the table below Go to G Signal Function Test Procedure Correct Reading L 5V Laser fire from controller 5vdc to controller Touch this pin to ground and the laser will fire if the LASER SWITCH is on. With DVM on volts scale read to ground Laser fires 5vdc G Ground With DVM on volts scale read to ground 0VDC 24V 24vdc to controller With DVM on volts scale read to ground 24vdc 5V 5vdc to pot With DVM on volts scale read to ground 5vdc I Analog power With DVM on volts scale read to ground. Voltage varies as pot is turned 0-5vdc G Ground With DVM on volts scale read to ground. 0vdc L Test Switch Push & Hold Laser Test Switch & measure with DVM on volts scale to ground. P Laser Switch With switch On reads on volts scale with DVM to ground 0vdc 0vdc G Ground With DVM on volts scale read with to ground 0vdc AC AC AC from mains AC from mains Caution: Read HIGH VOLTAGE with DVM on AC voltage scale across these pins G Ground With DVM on volts scale read to ground 0vdc L- Laser cathode return DO OT MEASURE. Depends on country (120-220VAC) Proceed to H
Testing Methods After you measure you LPS inputs H If one or more of the voltages are incorrect, the table below provides more things to try. The tables below are organized by function. In all cases trace and verify the wiring and all connections back to the source of the FUCTIO. Signal Function Further Checks Go to L Laser fire from controller If this test fails and the laser does not fire while running a job the problem is likely the controllers output 5V 5vdc Any time 5V is incorrect your LPS is not operating correctly G Ground Any time ground is not 0V its likely there is a ground connection missing 24V 24vdc If 24V is not correct its likely from a fault in the supply. K Go to test procedure Check wiring Go to test procedure O O I Analog power If the voltage is not changing with pot position check the wiring and/or test/replace the pot L L Test Switch Check the wiring and test the switch M P Laser Switch Check the wiring and test the switch M AC AC AC from mains AC from mains Check the input power and the main fuse located in the plugs housing I P Q L- Laser cathode return DO OT MEASURE. If voltages are OK and problem not fixed, try? I R
Troubleshooting Your LPS: I If you have landed here its possible that your LPS is bad (:. Here are some additional checks Generally speaking the LPS is not a repairable item but here are some addition checks to be sure it should be replaced. Check each of these and correct them if they are incorrect. Then retest to see if the supply works. Turnoff the machine Unplug the machine Unplug the leftmost connector on the LPS. On the left side of the LPS, verify that you have this switch in the correct position for the mains voltage you are using If not set it correctly Remove the LPS cover On the PCB check this fuse to see if it is blown by using me procedure (). You can replace the fuse but most likely it will blow again. If it blows again your supply has a serious internal problem & likely needs replacement S
Troubleshooting Your Controllers Output K Troubleshooting your controllers interface to the LPS is complex and may require advanced equipment. Until we have created simple tests you can get help at the K40 forum. But in the meantime here are some additional things to check. R The L signal is not wired correctly from the controller The controller is not configured properly for the port being used for PWM (L) The controllers PWM configuration is not correct The Laser module in the configuration is not enabled. The job is not sending anything to the controller The S value is 0 in the gcode. R
Testing the pot & switches L This is the part you are testing TUR OFF POWER If you have this panel go to: C Disconnect the POT from its circuit by unplugging it from the LPS. With the meter as shown to the right. Turn the pot fully in both directions and the resistance (ohms) should change from 0 to max. On some pots the max is 1000 others it is 5000. Use this scale M These are the parts you are testing. TUR OFF POWER Disconnect the switch/pushbutton by unplugging the harness from the LPS. With the meter connected across the switches pins. Verify that when the switch or button is activated the meter reads 0 ohms. Use this scale
Testing the Digital Panel C Caution: This procedure must be done with the power on. Caution: This If you have this kind of procedure must be LPS connect the meter done with the power like this on. GD I If you have this kind of LPS connect meter like this GD At the control panel change the digital values with the 4 digit controls I As the digits are increased/decreased the voltage on the meter should change in the range of 0-5vdc If the correct voltage is not present or does not change try : Use this scale Check the wiring continuity between the panel and the I pin of the LPS. More Info: Replace the Digital Panel R
Testing the Internal Fuse This is the part you are testing. TUR OFF POWER Disconnect the AC connector Measure the resistance across the fuse. If it's not 0 ohms then the fuse is blown. Use this scale
Dangling endpoints G You got here because your LPS is not a type supported by this document More help can be found here: R You got here because you need more help. https://plus.google.com/co mmunities/1181134835893 82049502?np=wawcHeygme zumb6fhbqhgengwuh izmdtjgcqf2amv2dzeje https://donsthings.blogspot.c om/ S You got here because you have an internal problem with your LPS. You can buy a new one or try a repair. Rrepairing-k40-lps
Testing Methods ote: your DVM may not be the same as the one depicted in these drawings. Adapt this content to your particular DVM scale, connections and operation.
Using a DVM to Measure 0-5VDC Use this scale Connect to ground Connect to the pin expecting 0-5vdc
Using a DVM to Measure 0-24VDC O Use this scale Connect to ground Connect to the pin expecting 0-24vdc
Using a DVM to Measure 120 VAC P Use this scale Connect one side of the AC expecting 120vac Connect to the other side of AC expecting 120vac
Using a DVM to Measure 220 VAC Q Use this scale Connect one side of the AC expecting 240VAC Connect to the other side of AC expecting 240VAC