lincoln tig 300/300

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I bought this welder about 15 years ago, used. It's bin good up till now. I was welding aluminum and started to feel the HF coming                                                        through the tig handle just a little. At first I thought it was just a pinched nerve in my hand giving me a little tingle, but it got worse.I layed down the torch on a leather glove and could see a small arc coming through thehandle to the slide switch I mounted to the handle and connected to the remote controlplug. { The reason for the switch is to turn off the power to the torch to get into tightplaces without accidentally striking an arc.} Well, now all I can get out of the torch is alittle spark with no amps {heat} on all settings, with or without HF and I did replace the old handle.  It's rating input is 230 volts 117 amps and code # 7288. I'm a machinist not an electrician  but have a friend that can help me out, with any help the group can offer to repair the problem. ThanksGettenby
Reply:I wonder if the device which electricly isolates the high voltage of the HF has broken and gradualy lethigh voltage leak into the huge windings which supply the low voltage/high current for making the heat.Seems like if high voltage leaked over it might burn shorts theough the varnish on the BIG windings andshort the windings internaly. (?)   Maybe you can find out from its manual or from lincoln what the resistance should be across the seccondary half of the main transformer to help determine if it isshorted (lower resistance than normal)   Not sure what kind of device used to prevent HV from feeding back into the main windings.........Maybe someone else knowing more than me can help there......Tim
Reply:Many times I have found this symptom when the tig torch lead goes bad. Hi-Freq will get through the torch but welding current will not. Try stick welding with the welder, that will tell you if it is an output problem or a tig torch problem. If you are using a remote current control you could put it in panel control to eliminate that.Gary Haunemail  [email protected]  http://haunsystemsrepair.com