Lincoln Pro-Cut 55 Problem

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I just purchased a used Lincoln Pro-Cut 55 at auction five days ago.  The plasma cutter looks to be in excellent condition, including the torch, and I don't think it has had much use.  I bid on it knowing it needed repair.  The unit turns on without problem and no errors.  When I pull the switch on the torch, air comes out, but it doesn't light off.  I replaced all of the consumables on the torch with no improvement.  I'm hoping someone has some ideas to try.
Reply:you might want to make sure that the consumables are correct and all the parts are there.  sometimes after market parts are "interchangeable" but won't make the machine work.  After that, I'm at a loss once you get into the internals.
Reply:Make sure everything is properly seated and tight on the business end of the torch.
Reply:

Originally Posted by BillE.Dee

you might want to make sure that the consumables are correct and all the parts are there.  sometimes after market parts are "interchangeable" but won't make the machine work.  After that, I'm at a loss once you get into the internals.
Reply:Be patient, grasshopper.  Someone will chime in.  In the meantime have you searched for inherent problems with that machine or contacted a local dealer?
Reply:I have one bought it new hardly ever used it used it one day went to use it next day never has worked since sent it to repair shop they sent it back as no parts available so good luck
Reply:Evidently there is an inherent problem ... just saying.
Reply:Take the code number to the Lincoln electric web site. under the support tab select find parts. enter as a guest. now enter the code number in the box then select porcut55. this will open the service navigator. should at least show the owner's manual, parts manual and the service manual.From the service manual find the torch and output pcb tests. When you try to fire the torch, then release the trigger. does the torch handle makea couple of soft bumps? this is the solenoid making the electrode move.If electrode does not move, the torch will not fire.Using the service manual and a DVM you will want to try to measure the out put voltage. follow instructions in the manual. be careful voltages can be high.
Reply:When I try to fire the torch I hear a very slight click and then the air starts flowing.  I don't feel anything like a soft bump.  Lincoln won't give me access to the service manual for the unit.  Apparently, this is now restricted to Lincoln employees and Business Partners.  I did find a copy of a Pro-Cut 55 service manual on the internet, but it is for Codes 10473 and 10474.  My code is 10571.  I don't know how much difference there is between the manuals.  I couldn't find a manual online that was specifically for Code 10571.Last edited by glcaines; 02-26-2021 at 04:40 PM.Reason: More info
Reply:Here's the operators manual that shows some other codes that are likely very similar. Also the parts list. I found a service manual for codes below 11000https://www.lincolnelectric.com/asse...oln3/im637.pdfhttps://lincoln-is-viewer.ptcmscloud...QyNzQ3ODc1MjJ9https://www.manualslib.com/manual/95...-A.html#manualLast edited by Welder Dave; 02-26-2021 at 06:10 PM.
Reply:

Originally Posted by Welder Dave

Here's the operators manual that shows some other codes that are likely very similar. Also the parts list. I found a service manual for codes below 11000https://www.lincolnelectric.com/asse...oln3/im637.pdfhttps://lincoln-is-viewer.ptcmscloud...QyNzQ3ODc1MjJ9https://www.manualslib.com/manual/95...-A.html#manual
Reply:Look for the torch test. Then remove the cover. on the left side is the output pcb. There are LEDs on it. Find the page in the manual that will tell you what they are. look the the torch solenoid LED and the trigger LED. watch them when you try to fire the torch. Trigger light should turn on then off with trigger. solenoid light should turn on then flash a couple of times when trigger is released.If it flashes and you don't feel the bump in the torch handle.then you will have to open the handle and check the operation of the solenoid and the torch electrode piston. remove cap and reinstall.watch piston move. and with cap off push on electrode by hand and see how it moves. also see if electrode will fall out of torch by its self with cap removed. if it doesn't the swirl ring will have to be replaced. The knurled ring unscrews and the swirl ring is attached to it. with old age they swell and the electrode drags on them and it causes torch to not fire. With torch handle open be careful of high voltage between the pilot and cut circuits. If you press the trigger.
Reply:Thanks for the help!  I performed the Torch Continuity and Solenoid Test according to the test procedures.  Everything passed within specs.  I then applied 12 VDC to pins 2 and 3.  I couldn't feel the solenoid operating in the torch.  If I put the torch up to my ear in dead quiet, I can hear a very slight click when I pull the trigger.  My ears are good and I could barely hear the click.  I don't feel any bump in the handle.  It sounds to me like I might have a problem with the solenoid. This would match with what the troubleshooting flow chart in the service manual indicates as well.  Can you normally feel a bump in the torch, or is the very faint click I'm hearing normal?I then performed the tests outlined above and in the service manual for the Output Board Trigger Circuit Tests.  The LEDs all lit as described.  I'm almost positive the solenoid in the torch is bad.Last edited by glcaines; 02-27-2021 at 07:00 PM.
Reply:Don't think you can feel the solenoid move. but you can feel the electrode when it moves correctly. If you can figure away to test for 12 volts at the solenoid inside the torch handle with out touching any of the power circuits. Bare copper tubing and torch head. Between the body of the torch and the wire on top could be up to 300vdc. With the handle off and torch on a table. Connect to solenoid wires and pull trigger. Must have air supplied to plasma so torch could fire. So make sure nozzle is aimed away from everything. See if you get a pulse of 12vdc. and you can watch the connection wire and if the electrode moves you will see it. with power off. pull on electrode connection and see if you can move it a little. if it will not move, torch will not fire. If air flows and voltage gets to solenoid, electrode does not move then solenoid might be bad. When you screw on the retaining cap. you should see the electrode connection move a little.Be very careful. these tests are dangerous.
Reply:

Originally Posted by ccawgc

Don't think you can feel the solenoid move. but you can feel the electrode when it moves correctly. If you can figure away to test for 12 volts at the solenoid inside the torch handle with out touching any of the power circuits. Bare copper tubing and torch head. Between the body of the torch and the wire on top could be up to 300vdc. With the handle off and torch on a table. Connect to solenoid wires and pull trigger. Must have air supplied to plasma so torch could fire. So make sure nozzle is aimed away from everything. See if you get a pulse of 12vdc. and you can watch the connection wire and if the electrode moves you will see it. with power off. pull on electrode connection and see if you can move it a little. if it will not move, torch will not fire. If air flows and voltage gets to solenoid, electrode does not move then solenoid might be bad. When you screw on the retaining cap. you should see the electrode connection move a little.Be very careful. these tests are dangerous.
Reply:I received the new solenoid and installed it in the torch handle.  It is now obvious that the old solenoid was defective as I can now feel the movement in the handle and with the handle open I can now see movement.  The bad news is that the bad solenoid is not the only problem because the torch still won't fire.
Reply:Time for output pcb tests. try to measure the output voltage. be careful. voltage is high. 100vdc if torch fires and up to 300 volts or more if torch doesn't and tip is not touching the electrode. A shorted torch will have low voltage.Complete the tests in the service manual. before trying to measure the torch voltage.
Reply:

Originally Posted by ccawgc

Time for output pcb tests. try to measure the output voltage. be careful. voltage is high. 100vdc if torch fires and up to 300 volts or more if torch doesn't and tip is not touching the electrode. A shorted torch will have low voltage.Complete the tests in the service manual. before trying to measure the torch voltage.
Reply:The Fluke is reading odd because of the plasma is an inverter.I use an inverter certified meter and it acts up sometimes. But if you turn the auto range off they work better.Now you need to pay attention to the timing of when things happen.The inverter should turn on soon as the trigger is pulled then the air should turn on.Can appear to almost be at the same time. But if air turns on before the inverter the torch will never fire. The act of blowing the tip and electrode apart causes a spark that starts the plasma flame. So the output has to be on first.If you are reading 300vdc at the torch then the tip and electrode are open. Can't make a spark.
Reply:As an update, I've decided to take the unit to a Lincoln repair facility.  I'll post what I find out.