mike 109444
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You could try A1Plant down at Newport. 4mt MB15 = aprox £43. That's where I got my last one. Take cash if you go cos they don't have card falicity on site but can take card order via ebay!
- Thread starter Exuptoy
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Exuptoy
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I have had a loan of another euro torch and have dropped the gas pressure a little to compensate but my welds with it look terrible and are full of holes along the top of the weld! Is this caused by too much shielding gas? I have gone back to my partially blocked one and it is back to normal! The weld looked horrible with holes and troughs everywhere.
Unfortunately my reg is a converted CO2 one with no flow reg so I cannot tell the flowrate.
Unfortunately my reg is a converted CO2 one with no flow reg so I cannot tell the flowrate.
Exuptoy
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More grief I'm afraid. Not down to the welder but the numpty who repaired it in the past.
This week it stopped working but would still feed wire. Contactor not pulling in. Chased the wiring to the speed control board where the aux 30v transformer feeds the board via the trigger which feeds a rectifier which is split to feed the contactor which calls in the gas valve/main transformer and the speed control circuit.
Looks like said numpty has fitted a 24vAC contactor instead of DC! This has swollen the plastics in the coil due to overheating which has caused overheating on the board and melted the power track on the SC pcb. I bridged the burnt track but now there is 24v but I need a contactor to see if all is well. I reckon the rectifier is now fried too as there is no longer a wire feed.
Just purchased a contactor and new B80C5000 3300 rec on the bay of E.£13 inc delivery for the contactor and £3 for the red. Lets hope this sorts it.
Should this not repair it, can I purchase a universal speed control board and pot which will still work with my 24-30v torch feed, 24vdc feed motor and 24vdc contactor output? (Can purchase an ac contactor if that is standard fare).
This week it stopped working but would still feed wire. Contactor not pulling in. Chased the wiring to the speed control board where the aux 30v transformer feeds the board via the trigger which feeds a rectifier which is split to feed the contactor which calls in the gas valve/main transformer and the speed control circuit.
Looks like said numpty has fitted a 24vAC contactor instead of DC! This has swollen the plastics in the coil due to overheating which has caused overheating on the board and melted the power track on the SC pcb. I bridged the burnt track but now there is 24v but I need a contactor to see if all is well. I reckon the rectifier is now fried too as there is no longer a wire feed.
Just purchased a contactor and new B80C5000 3300 rec on the bay of E.£13 inc delivery for the contactor and £3 for the red. Lets hope this sorts it.
Should this not repair it, can I purchase a universal speed control board and pot which will still work with my 24-30v torch feed, 24vdc feed motor and 24vdc contactor output? (Can purchase an ac contactor if that is standard fare).
Exuptoy
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Right, just swapped out the contactor and it now switches BUT I still have no wire feed. All components on the board check out except the 555 IC which I am unable to test. I can get a 555 texas instruments IC chip of enay for pennies. Are they all the same?
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Yes the're all the same, worth picking up an 8 pin DIL socket to save damaging the IC when soldering.
Exuptoy
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mike 109444
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If you wire feed motor connects onto where the 2 red X's are then I would suspect the transistor mounted to the heatsink (bent ally plate) case T03 type 2n3055 maybe? Also I would move the wire repair wire so it sits ontop of the burnt track cos at moment it's sat over the 30Vac tracks so if it goes again = short of transformer!!
Exuptoy
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Here's the transistor.
It did check out ok using the diode test on the multi for polarity/bias. I'll do the IC then if no joy I'll take the board to a specialist for repair. I can only do so much. lol.
So far the cost to repair this has been £13 for the contactor and £3 for the rec which hasn't failed and £1odds for the IC so not into it for big money yet.
Also the wire has been moved.
It did check out ok using the diode test on the multi for polarity/bias. I'll do the IC then if no joy I'll take the board to a specialist for repair. I can only do so much. lol.
So far the cost to repair this has been £13 for the contactor and £3 for the rec which hasn't failed and £1odds for the IC so not into it for big money yet.
Also the wire has been moved.
Exuptoy
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Just got my chips and sockets this morning so I tidied up the board a little and using some solder wick I removed the IC and fitted the new socket and plugged in the new IC.
Still no joy. Just purchased a new BDX18 transistor at Mike's suggestion for just over £4 so I'll try that on Friday when it arrives. Still not into it for big money so it has to be worth a try.
Still no joy. Just purchased a new BDX18 transistor at Mike's suggestion for just over £4 so I'll try that on Friday when it arrives. Still not into it for big money so it has to be worth a try.
mike 109444
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That won't helpJust removed it from the board and the base pin is open circuit to everything and at both polarities. I'm hoping this is gonna cure things. Fingers crossed.
Exuptoy
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That won't help
What am I looking for Mike as the last time I had anything to do with transistors, diodes and resistors I was at college 20 years ago lol.
I could google it but I'd rather ask someone who deals with this stuff regularly.
Cheers
Lyn
mike 109444
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From your second discription of testing, using the diode test on your meter then it may be ok. Usually expect to see in a circuit like this a tranny go open or dead short(as per your first statment) I don't deal in my work (employment) now with this sort of thing (board swapping usually if faulty) last time I dabbled would have been about 8+ years ago. I would expect to see a flow (which is what your meter is creating / measuring) between the base and emitter. Then also a flow between the base and collector. But with no bias voltage on the base you would not see a flow between the collector and emitter. Note this transistor is a darlington pair which are two transistors connected togeather in one package so may give slightly different readings than a single tranny.
The transistor must have been passing some high current (enough to fry the contactor coil!) and that would have been from the emitter - collector junction hence the burnt track that the collector is screwed to.
The transistor must have been passing some high current (enough to fry the contactor coil!) and that would have been from the emitter - collector junction hence the burnt track that the collector is screwed to.
Exuptoy
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Ok thanks. I've just also removed the small transistor in the bottom corner and this one doesn't check out only on one pair. This is I think a 2n2219 npn switching tranny(I can only read N2219 but I'm sure I'm correct) I'm gonna do both for the minimal outlay involved.
Just notice the one pair that does read 0.5v, in the opposite direction reads 2.5v????
Just notice the one pair that does read 0.5v, in the opposite direction reads 2.5v????
mike 109444
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It prob is a 2n2219 as the 2 indicates it's a 3 connection device! that why a 1n4014 (a diode) is a 2 legged device If I recall it was the japanees standard or sombodys.... I can feel the grey cells dying in there droves tonight 
Exuptoy
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It prob is a 2n2219 as the 2 indicates it's a 3 connection device! that why a 1n4014 (a diode) is a 2 legged device If I recall it was the japanees standard or sombodys.... I can feel the grey cells dying in there droves tonight
Haha!
I just hope this sorts it. Shame for this welder to go to waste. 