Hey guys,My buddy just gave me his welder which is a Lincoln welder. The reason why he gave it to me is because it was not welding correctly based on making bad welds. From the picture it appears two capacitors gave out and melted. I cannot find the correct size of the capacitor since half of the information on them are burnt off. Thank you for you time and is much appreciated. Questions that I have:1) Can this board be salvaged? Does anybody have a picture of a SP-100 board? 2) Can you buy replacements boards online?3) Any tips you can offer on this?Picture 1
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Reply:Are you sure they are caps?Im not a Lincoln guy, but on Miller's boards those are thermistors aka thermal fuse/switch.If this is the case, and the sp100 does not have a thermal switch inside the transformer for over heat shut down protection, then I would guess your friend ran that machine well past it's duty cycle and nuked the board.Until you have the component(s) desoldered from the board and remove the soot, then you wont know if the traces can be tested for continuity.Good luck. Im sure guys that know more about the lincolns and electronics in general will reply soon. Just be patient.Miller Dynasty 200DXMiller Spectrum 250DMiller Millermatic 200Bunch of old blue dinosaurs....
Reply:I believed it was ceramic disk caps but I could be very well wrong. Not sure how old a SP-100 would be and with any indication I am guessing over 10 years old. They must of not had a heat shut down protection on it which caused them to go bad. Do you have a suggestion to buy a new board at?
Reply:If you end up trying to replace the board, dig a bit to find the p/n in the Lincoln online parts directory. http://www.lincolnelectric.com/asset...LN1/LEMenu.pdfEastwood TIG 200 AC/DCLincoln SP-125 PlusHitachi Dry Cut Saw
Reply:I tried using that website and it isn't working for me. I called a place to see if I could get a board from PLC and they said no. Does anybody on here sell that stuff?
Reply:Ceramic Disc capacitors C1 and C25..0047uF1400VDC125VAC20%PM me an email address and I'll send you a present.Last edited by duaneb55; 11-18-2013 at 07:58 PM.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:I would be more curious about what made it draw enough current to blow the terminal off.http://www.electro-tech-online.com/a...ual-pdf.82027/
Reply:Bluewelders is showing off again. His link is the same Service Manual I was going to email so . . . I'd be curious too and my first guess is the previous owner hooked it up to 230V. Trying to get more output. MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:That's what I am curious as too on why and how it happened. What sucks is my buddy bought it from a guy but had no prior knowledge about the welder and then found out it was acting goofy when welding and thought this was it. Thank you bluewelder for the service manual. Now I see it talks about the board but not sure who or how to find the board. I googled the crap out of it and I can't find any used or even new? duaneb55 thank you for the right caps. Do you think the board is even salvageable since it appears you have experience on this kind of stuff.
Reply:If C25 failed ( shorted) while welding, The welder would go wide open until cap or trace burnt open. C1 is just a electrical noise filter. For line voltage. Lives across the line.C25 is part of the output control system and is parallel to the electronic switch. (light dimmer type circuit). Far as I know the G1842-2 pcb is no longer available new. 31 and 531 are on the same side of the line with the control triac connecting them. The cause of the burnt marks might be elsewhere on the pcb.
Reply:Sorry duane,should have known you had one in your libraryOccasionally a crimp connector will start to have High resistance and burn up and arc,but it is always good to check before burning copper off of the board.
Reply:Originally Posted by ccawgcIf C25 failed ( shorted) while welding, The welder would go wide open until cap or trace burnt open. C1 is just a electrical noise filter. For line voltage. Lives across the line.C25 is part of the output control system and is parallel to the electronic switch. (light dimmer type circuit). Far as I know the G1842-2 pcb is no longer available new. 31 and 531 are on the same side of the line with the control triac connecting them. The cause of the burnt marks might be elsewhere on the pcb.
Reply:It is up to you. If you can find the burnt parts replacements and want to try changing them go ahead. Part on repairing equipment is sometimes replacing the obviously bad parts and then trying to use it and see what happens. Chasing and repairing each problem as it pops up until all is fixed. Sometimes we can get lucky and see how a circuit works and can tell why it failed. We then are able to replace all the bad parts the first time. AS a repair shop we replace pcbs instead of repairing because my cost of a new pcb is only a little higher than the cost of having a pcb repaired. Repaired pcb have a higher labor cost because they sometimes take 2 or 3 times sending them back just to try and complete the repairs. We one time sent off a XMT 304 display pcb to be repaired. It worked ok but display had dead segments. Got back a dead pcb that would not control the welder anymore.Your labor is cheap, so if you want to replace thee caps and all the parts around them should cost to much. Sometimes TV repair shops will help get parts and even solder them in for cheap. Even if it doesn't work. Good luck and let us know how it turns out.
Reply:I would totally replace the board but that's the problem is I can't find one which is a huge bummer. Do you have a suggestion on a place I could get this board from and how much?
Reply:The good news is that the power section on this board is optically isolated from the rest of the board, so the fault could not have gotten into the rest. Hence, even if you replace everything in that section, it should be pretty cheap and easy, and good odds of success. As others havd stated already, about the only thing that can burn those caps would be cap failure, for whatever reason.- Tim
Reply:That charred area of the board can conduct. Usually a good board repair on that type of damage includes grinding out the charred area and filling with epoxy.
