Jasic CT 312 DC Inverter TIG Welder

[Bekker]

I've bought this machine in 2009 and it did for me what I needed done. Tonight though I heard a strange noise..., after unplugging I opened it up, plugged in again and switched on - smoke!
It starts smoking from a specific part (no idea what it's called) on plasma and weld functions. Please see photos. First photo shows part is situated at the top and middle of machine. Second shows part from above.
I've kept machine clean with air and did moderate hard work with it. If I can fix it, I'd do so.... Any advice will be welcome!
Suggestions on new machines would be great as well - taking into account that I'm very low on Pounds at the moment.
Thanks!

 

[mike 109444]

Think you will find they are capacitors. If they are poorly rated (max voltage) they may break down over time. If you can get a view of the side you should be able to see the markings that will give you there values ect. Then punch in to Google, may even get them at maplins

 

[Bekker]

Thanks! Will do so asap!
Cheers!

 

[Bekker]

Capasitor

Hi there!
Capacitor SR 475K 400V
I've found - MPP 475K 400V P25MM - in a Google search.
Can this do?
If the Voltage can be considered as poorly rated, can I replace this with a higher Voltage Capacitor?
Thanks

 

[shenion]

That is a 4.7uf at 400V polyester or polypropylene film capacitor.

Higher voltage will work but would likely be bigger.

 

[ilovemygt35r]

id change the cap like for like values, it may be an electrolytic capacitor, one side is negative, one side positive, get it wrong may bang!.
whats the component between the two caps (black thing, looks a bit like a choke) looks like its connected to the two caps.

 

[mike 109444]

As Shenion says a higher rated one will prob be bigger. You might even find the correct value ones from a different manufacture could be bigger. What ever you get, try and move the left one in your second pic away from the heatsink that it looks to be pressed up to (the aluminum finned device) as it's probley cooking the cap. You should also find the caps are not electrolitic so can go either way round.

 

[mike 109444]

Try search on ebay for 4.7 400v Metallized Polypropylene. Or If you can find one a TV spares/repair place should have one (You do have TV down there now?) : )

 

[Bekker]

shenion - thanks!

ilovemygt35r - I'll replace the next with the print towards the same side - hoping that will be correct polarity?!
Not sure which black thing you're referring to - there are wires and a black rubber-like protective around another wire...

mike 109444 - So it will OK installing a higher voltage one?
There is space in the box for me to move both away from the heat-sink (I assume you are referring to the aluminium square with the yellow insulation?)
I'll solder them in on longer wires.., insulating the wire? This a good plan?
You are joking - TV, down here in Cornwall! No, we do not have one - principles :-)
I can find a dozen or two though. I'll have a look! Thanks!

Gentlemen, thanks for all the advise! Most of it a little above my experience, but much appreciated! I'll post my progress!

 

[mike 109444]

The "aluminium square with yellow insulation" is a transformer. No what I was refering to was what I now see (having looked again) is only a white header plug (the one with the red and black wires going into it). Some electronic devices will just fail over time. Most manufactures will fit the lowest value/COST device they can get away with. If you save a penny on every other device in a box like that and then multiply by number of boxes produced it soon adds up. That's why a lot of the set top boxes for TV's would fail. Things like fitting a capacitor rated at 25v to a voltage rail of 12v so a slight surge of the 12v and pop goes the weasle or cap. Oh and a TV is a wooden box with a glass frount bit like a fish tank but not so intresting

 

[Bekker]

Thanks for that! No problem to replace, just want to do it properly and at a lowish cost! Will keep you posted on my progress!
No, we are the worst parents in the world - no TV, but I might get them a fish tank...

 

[penfold]

mike 109444 - So it will OK installing a higher voltage one?
There is space in the box for me to move both away from the heat-sink (I assume you are referring to the aluminium square with the yellow insulation?)
I'll solder them in on longer wires.., insulating the wire? This a good plan?

I wouldn't bother specifically looking for a higher voltage one but it won't do any harm. It isn't really necessary to move it away either, it probably died because it was defective rather than being overheated, but if you do be sure to secure it to something so it isn't flapping about and fatiguing its leads; a blob of hotmelt glue is good for this.

 

[Bekker]

Hi there! Welder fixed! Got capacitors from Hong Kong and replaced both - the blown one and the one next to it just to make sure!
Thanks everyone for your advice!

 

[vpug]

Hi
Well done that man, I bet your over the moon with yourself.
Thanks Vpug

 

[Bekker]

You bet! There was almost a moment of tears, but I noticed one set of wires not connected and wallah! As good as new - I hope! Cheers