Newbie having problems with a plasma cutter

Hi there, i've been looking at this site for sometime now so thought i might aswell register.

I'm having problems with a Telwin Tecnica Plasma 30 cutter. It's been working fine up till now, but i went to use it this morning and it won't go
If i plug it in and turn it on all 4 lights on the left of the panel flash on and go off then the green one comes back on followed about 1second later by the red one, the 2 amber ones between the red and green ones don't come back on. If i press the trigger a solenoid inside the machine clicks, if i flick the switch on left of the panel down(it's sprung loaded) i get a constant steam of air from the nozzle but it still won't start when i press the trigger.

Does anybody have any ideas as to the cause of the problem?

Silly question maybe, but is the air pressure set correctly and are the electrode and cutting tip in good order. Also a poorly fitted swirl ring can cause problems.
Non genuine consumables can also cause a problem.

All the consumables are genuine parts and all fitted properly, i know that they're OK as i've tried them in another cutter and they work in that one, and i've tried resetting the air pressure at various pressures.

It's got me stumped, it's worked well up to now, no problems in the last 3 years or so.

Just a quick update, I took the machine into the local welding suppliers for them to have a quick look at it and they say all the obvious things check out OK so it looks to be a problem on one of the PCB's and they are now waiting a diagram of the PCB's from the manufacturer.

Now we all know that new PCB's are expensive to buy, so what do you people reckon would be best now, Carry on regardless and get it repaired or not bother ? What would the price for a New PCB be or can the damaged one be repaired ? Does anybody here have experience of having to buy a new PCB or get one repaired and what would the cost involved be ?

Lots of questions i know but i really don't know which way to go with this.

Hi,

repairs might be better done by an electronics enthusiast rather than a 'shop' as they tend to take a bit of time and that equals money.

If it uses generic components then it should be fairly easy to check out individual diodes, transistors, etc. Any special 'componets' such as manufacturer specified chips will be a problem to source...hopefully there aren't any of those in there as this type of device tends to be used in lower powered kit (anything from a PC to a burglar alarm, etc).

If you've not done any of this type of faulting before then it can be a bit tricky getting started, difficult to advise, but we do have electronics guys on the forum. If you could post pictures of the boards then you may get some ideas.

The first thing is to check for anything that looks like it's been 'warm' ie, discoloured. Anything that looks 'loose' or dry joints. Circuit board tracks that may be cracked, etc. It would be better to touch an earth before touching the circuit boards to discharge any body static. It'd be even better if you had an electrostatic wrist strap to connect to the cutter case so you're at the same potential as the circuit board.

Do you fancy some basic electronics? Or would you prefer to find someone local?

How about a local Radio Ham? They tend to be very knowledgeable about electronics.

Regards
Peter

Edit: forgot the 'safety' note: Double check that the power plug is out of the mains socket and wait a few minutes for the capacitors to discharge. When you're inside the box, any big component with two wires could be a capacitor and they can sometimes hold a charge for hours (or days) after the mains is switched off, so be carefull what you're touching. These capacitors tend to be on the case or a separate circuit board near the mains input / main transformer, etc.

Originally Posted by peterd51 How about a local Radio Ham? They tend to be very knowledgeable about electronics.

Older ones might be; in recent times they've simplified the procedure for getting an amateur radio licence so more and more of them are little more than button-pushing CB radio types.
It was already getting that way when I got my G1 in '83...

The machine is still at thier workshop at the moment as they're waiting for a diagram for the PCB's to come from the maunfacturer before they can check the PCB's.
My main concern is how much is a reasonable price to pay for this machine to be repaired. I don't want to pay more than the machine is worth but i don't just want to throw it away if it can be repaired for a sensible amount.

I banged the cutting head of my Thermadyne unit which wouldnt work and it started. It is about six months old but i hadnt used it for 3 months. I did all the usual test and it all seemed ok so banged the main box, no joy, then tapped the head quite hard on the workpiece and away it went. Bit crude but it worked 4 me.

i would say to them do not go ahead with the repair until you have told me what it will cost and get a written quote off them not an estimate

Hi there,

I know this thread is a few years old, but I have recently picked up an identical model, with what looks to be the identical problem. Being in New Zealand, I cannot find anywhere that stocks spare parts for this model and there is very little information about it on the net.

I was hoping that Mr Jimbo found a solution to his problem with his unit and could pass it on to me.

Many thanks.