WeldAll LS-200PI Troubleshooting Help Needed

[jamesg302]

Hello, my name is James and I have a Longevity WeldAll LS-200PI that recently failed. The machine is a multifunction TIG (AC/DC), Stick, and Plasma cut machine. I like the machine and would like to repair it. However, I am unfamiliar with how to go about troubleshooting inverter welding machines. So, if anyone here can offer advice it would be greatly appreciated.

I last used my machine several months ago and it was working completely. Upon plugging the machine in and going to use it last week I found that it has a failure. The machine will not initiate an arc and the amperage control does not work. I looked for loose connections and any visible signs of component failure and found none. Symptoms are that when the machine is first turned on there is a slight buzz (2-4 seconds) from the rear near the fan, the overcurrent/overheat notification illuminates for 2-5 seconds, and the amperage displays a fluctuating 28-35ish. The overcurrent/overheat notification goes off and the amperage display settles to 34 or 35. Adjusting the amperage control knob has no effect on the displayed amperage. I tested the machine in stick mode as it is the most basic and the machine will not initiate an arc.

I need some guidance to help narrow down the possible problems and determine what to test and how. Attached are a few photos of the machine for reference. If anyone is interested in helping I have more photos and information that I can send. Thanks in advance for the help.

[jamesg302]

Surely there is someone out there who can help that has had similar troubles with a unit similar to this? Perhaps someone has a service manual for this machine or one like it that would at least give me some test points and reference values? Any information would be helpful.

[weldinghomer]

At the circuit board where the front controls connect, try pulling off all the connectors and reseating them. But be careful to make sure you put them
back exactly like they came off.
Sounds like a common line to this display / control board could be having poor contact.

[jamesg302]

weldinghomer,

Thank you for taking the time to offer your assistance. I will definitely try what you have suggested. Let me ask your opinion though. If the problem was isolated to the display then wouldn't the arc still initiate but simply not display the correct amperage? Or is there some internal error check that says any error could prevent the machine from operating until the error is resolved to protect components?

Your suggestion made me realize that I forgot to include another symptom. I already mentioned that the welder will not initiate an arc and that the amperage control knob has no affect on the amperage displayed. What I forgot to mention was that I also tested the foot pedal and it also had no affect on the displayed amperage. For example, normally, in stick mode the user can plug in the foot pedal and without any other items connected varying the foot pedal will cause the amperage displayed to vary in real time. That does not happen now. I can activate the foot pedal to any degree and there is no change on the displayed amperage and still no arc initiation.

[weldinghomer]

It may well be something else. The poor contact connector thing does fix a lot of stuff. A guy brought me the circuit board from a hobart mig and when i reinstalled it to troubleshoot everything worked fine.

I cannot really tell from the pictures but frequently a manufacturer will place the interface things like displays and knobs on one pc board and bring all the connections back to the main through a connector. So a bad contact can make jumping displays and unresponsive controls.

So many unrelated things being wrong makes me think a local power supply is not working. There may be board mounted fuses on the main board to check. They should read near zero ohms with a multimeter ( be sure to push the probes in to pierce the protective coating.

You are correct that a self protective circuit could be active in order to keep the smoke from emerging.

It looks like a really complicated machine but I will be glad to make suggestions as you find unusual things to report.

[jamesg302]

I greatly appreciate weldinghomer's help and insight on troubleshooting this problem. However, it would be great to hear from a few more people offering their experience. Is there no one who has had a similar problem with their inverter machine that could share their story of what failed and what was repaired?

Is the problem that this thread is not in the appropriate section? If it isn't what is the correct section and could a moderator please move it?

[DSW]

I've moved this to the Longevity section for you. Perhaps they can be of some assistance.

[longevity-inc.com]

Thanks for moving it here. So with this model, it looks like your control board may have failed. If you are not getting arc, you can check to see if the high frequency board has an arc inside the machine when trigger or pedal is pressed. If not, then most likely the top board will need replacing.

[jamesg302]

Longevity,

Thank you for the suggestion. However, I came to this website in hopes of finding more detailed support and troubleshooting information. While you suggest that the control board may have failed you have not provided any detailed diagnostic or service information that would allow me to perform component testing. While I appreciate the circuit diagram that you provided it does not match my machine model exactly and it does not contain any detailed component information. I am looking for a service manual that clearly describes the component locations, type, purpose, voltage ratings, etc. Surely information is available for my unit as it could not have been engineered without detailed schematics and documented component lists with operating voltages. I will send you a private message with examples of other manufacturer's manuals which have this type of information for your reference.

[longevity-inc.com]

Longevity,

Thank you for the suggestion. However, I came to this website in hopes of finding more detailed support and troubleshooting information. While you suggest that the control board may have failed you have not provided any detailed diagnostic or service information that would allow me to perform component testing. While I appreciate the circuit diagram that you provided it does not match my machine model exactly and it does not contain any detailed component information. I am looking for a service manual that clearly describes the component locations, type, purpose, voltage ratings, etc. Surely information is available for my unit as it could not have been engineered without detailed schematics and documented component lists with operating voltages. I will send you a private message with examples of other manufacturer's manuals which have this type of information for your reference.

Hi James,

Unfortunately, we do not have a service manual for the out of production models. We can however, diagnose your machine if you choose that option. Our trouble shooting over the phone/email is limited as you may understand. We do have a schematic we can send if you email tech@longevity-inc.com. Please let us know if you wish to send the unit in. For further and faster help, please email tech.

[jamesg302]

Longevity,

Thank you for the offer to diagnose the machine if I send it to you and for the offer of a schematic. However, I already have the schematic which you provided as I mentioned (i.e. the circuit diagram). As explained, my purpose in creating this forum thread is to find additional information for troubleshooting the machine. While I understand the machine is an earlier model and not current production, it was current production at the time it was being produced. At the time it was produced it would seem logical that Longevity would have obtained the detailed engineering information from the manufacturer, beyond a single page circuit diagram, under their license agreement. Therefore, that information should still be available today as archived reference just as any other manufacturer maintains documentation.

[jamesg302]

johncalbers,

I am sorry to hear of your troubles. However, Simon and his company have been fair in my previous dealings and continue to be fair today. The only reason I came to this website asking for assistance was that Simon did not have as detailed of documentation for my machine as I am looking for and I wanted to see if anyone else could offer more in depth information regarding components and testing.

[AKweldshop]

James,
Ignore that guy, he's a troll.

[johncalbers]

i rezemble that remark

[amessina]

I have the same issue with my LS-200PI. No parts and no schematics for the old blue units. I spoke to Jesse and he promised to have Daniel (Sales Mgr.) call me for a "special deal" since they admitted that shipping costs (~$150) plus diagnostics ($80) are not worth the expense. Basically they accept that a 5 year-old machine used by a garage hobbyist has gone thru its life. I find it a bit tough and find hard to believe that they have sold these units without any documentation from the manufacturers. Good luck with yours. Mine waas awesome while it lasted. Don't let yours sit idle. I let mine sit 3-4 months and it killed it!!! RIP Old Blue

[amessina]

I have the same issue with my LS-200PI. No parts and no schematics for the old blue units. I spoke to Jesse and he promised to have Daniel (Sales Mgr.) call me for a "special deal" since they admitted that shipping costs (~$150) plus diagnostics ($80) are not worth the expense. Basically they accept that a 5 year-old machine used by a garage hobbyist has gone thru its life. I find it a bit tough and find hard to believe that they have sold these units without any documentation from the manufacturers. Good luck with yours. Mine waas awesome while it lasted. Don't let yours sit idle. I let mine sit 3-4 months and it killed it!!! RIP Old Blue

[amessina]

Hi James,

Unfortunately, we do not have a service manual for the out of production models. We can however, diagnose your machine if you choose that option. Our trouble shooting over the phone/email is limited as you may understand. We do have a schematic we can send if you email tech@longevity-inc.com. Please let us know if you wish to send the unit in. For further and faster help, please email tech.

I emailed tech support and requested this schematic that you are mentioning and they never even replied. Any help is appreciated