tig not working

[Uncle Fester 55]

Hello to all.
Im a forum Virgin so please bear with me. Im no use giving tech help either, im not even any good at welding, but i have a go, but i do have a couple of welders, and one is faulty.
The make is as above, purchased used from a friend???, i used it once and now a problem.
Its a Tig as i am sure you all know, i was using it in MMA, arc welding to me. Working fine, mighty fine i might add, made my old oil cooled look like what it is, old hat, (but still working). Now all it does, is power up, red power light on, fan running, it looks to me like an overheat light at the side of the power light, flashing.
No power to strike an arc, but i thought i got a very slight tingle when i touched the electrode and earth with my hand.
Can anyone help?

Fester (john Blackpool, kettle always hot)

 

[mike 109444]

Don't stick your hand on it try a meter! Will give better results (how many volts does a possible tingle equal!). Beg, borrow or buy!!! a basic meter. Connect one lead to your earth clamp and other to rod holder and set meter to DC and say 200v. See what reading you get If now't or very little (less than 20v) then try meter on AC and see what you get. Could just be duff earth lead or rod lead (try spare if you have one)

 

[Uncle Fester 55]

Cheers mike, i have a meter but had no idea where to start with testing. I will check and get back to you.

 

[NotANormalCoder]

FYI, extract from the service manual (which I am not at liberty to hand out, sorry):
A) When the machine is turned on, the power relay on the pre-charging board (7) does not
close, the red block LED mounted on the circuit (36) remains lit, and the yellow thermostat
LED – also mounted on the circuit (36) begins flashing at a rate of approximately 1 Hz.
In this case, the machine is in a program-controlled block. This may be due to two shortcircuit
conditions detected by the machine processor during the starting phase:
1)Short-circuit on the output section.
2)Short-circuit on the torch start command section.
NOTE. Obviously, any short-circuit caused by the user while turning on the machine will block
it. In particular, this blocked condition is activated if the machine is turned on with the
output already ready for welding (for example: electrode resting on the bench with the
earth clip attached), or with the torch trigger already pressed.

Sooo, disconnect torch switch or footpedal plugs, as well a torch and earth, then try again. Could be failed trigger switch or shorted leads.

If it's not any of the above, then it's a major problem with one of the PCBs. You'll have to send it somewhere that repairs these.
Sorry I cannot help any further.
Dave

 

[Uncle Fester 55]

Thank you for that. I was attempting to use in MMA mode, earth return and electrode holder only. I have unpluged the leads and re-started the machine, the fan runs, red power light on, yellow flashing as you said. I have not had chance as yet to try with a meter, but will get back to both of you when i have.

Thanks again, John.

 

[Uncle Fester 55]

I have checked over the welder as requested. When i power it up, i get 21.6 volts DC across the + and -, tried the meter on AC and got no reading. I get the 21.6V reading in all the function positions, tig, mma etc. As previously mentioned, i have a yellow flashing light on next to the red power light on the front all the time. Something else i noticed tonight, when i turn the machine of on the power button, the red light and flashing yellow remain lit for about 5 seconds after power of switched, and the + and - stay with 21.6V until the lights go out, is this any help to solve it.
John.