My Plasma Died (But I Managed To Fix It!)

[Wendelspanswick]

After all this talk about cheap plasmas dying and me boasting about how my 5 year old CUT50 was still going strong I went to use it today and although the torch would trigger the air there was no cutting action.
I checked the consumables and for continuity in the torch and the return which were all OK.
I decided to whip the covers off and if I couldn't spot anything obvious I would get myself a new one as this one had earned its keep.
Covers off and I quickly spotted that a 1000uf 50V electrolytic capacitor on the top board had a horrible brown crust over it, I checked my junk box and found a new 1000uf cap but it was only 35V which I didn't want to risk using.
I went through my pile of old PCB's and found a 50V one but it was physically larger which meant I had to shave some plastic off the adjoining connectors, during which I time I managed to knock a trim pot off the board snapping the pins... aarrgghh!
I knew I had no spare trim pots but then it dawned on me that as the trimpot was already set all I had to do was substitute a resistor for the measured trim pot value.
I soldered the cap and resistor in and reconnected everything and it works!
For future reference here's a PIC of the offending board with the new cap and resistor soldered in and the offending cap on the bench.

 

[eSCHEn]

Nice one

 

[slim_boy_fat]

I wish I knew as much about electrickery as some of you lads.

 

[rtbcomp]

Thanks for posting! That cap probably just died of old age, and/or could have been under-specified

 

[cumbriasteve]

Well done you. it must be a satisfying feeling getting it working again.

I can fix most things in life and can solder as good as required but all those little round different coloured thingy's mean nothing to me, I really wish they did, I often regret not learning more about electronics, perhaps a night class would be interesting and beneficial if there is such a thing.

I suppose I can always ask here though

 

[Richard.]

Another 5 years on the cards then. I'm completely dateless with stuff like that and unless I find a 9 foot Python sitting in the bottom eating it's way through the internals I'd struggle to see if anything was out of place. Nice one.

 

[123hotchef]

well done i now have 2 of you to help me fix mine if/when it brakes

 

[skotl]

Good work! It''s a tremendously satisfying feeling bring something back from the dead, isn't it?

...as the trimpot was already set all I had to do was substitute a resistor for the measured trim pot value

Good point! That probably wouldn't have occurred to me