cosmo 145 gas/gasless

[davewebb1070]

Help !!!! worked fine yesterday when i replaced new wire , come to use it today and it powers up and the fan runs but nothing no wire feed or arc , motor on wire feed works on 12v battery , cleaned and checked all connections, torch switch and wire ok , on reading many threads its looking like the circuit board can anybody help !!!!

 

[shenion]

One thing to try is toggle the power setting switches. they can get bumped and be left in a mid position.

 

[Sean]

^ what he said its a design "feature" so you cant just plug it in and start welding
flip all the switches a few times.

is the blue wire with the lucar terminal in the torch handle OK have you continuity along its length? is the spring steel "switch" triggering and contacting the brass block?

 

[davewebb1070]

cheers Scott and Sean had another hour on it tonight tried the power settings switch a few times had the meter on the blue wire and thats ok , on the look out for a pcb or someone that can check it out and repair it

 

[shenion]

There is not much to the PCB.

The most common failure is the transformer. That is easily tested with a meter.

 

[davewebb1070]

cheers scott how would i be able to do that , any suggestions or websites that will show me step by step

 

[shenion]

Measure the resistance of the primary and secondary windings.

Post a picture of the back of the board and I can point out where they are.

 

[davewebb1070]

think i am doing this right with the photos , also i have read on one of the websites about some green gung over the board mine as that as-well see photos

http://www.mig-welding.co.uk/forum/album.php?albumid=1450&pictureid=8057
http://www.mig-welding.co.uk/forum/album.php?albumid=1450&pictureid=8058
cheers scott hope photos help !!!

 

[shenion]

On the board:


Measure resistance between 1 and 2 and between 3 and 4.

Most likely there is no connection between 3 and 4.

 

[davewebb1070]

hi Scott yes pal you was spot on 034 between 1 - 2 and no continuity between 3 - 4

 

[shenion]

I was going to bet on 3-4 The primary windings are real thin and break or corrode off easily.

You'll have to find a 230 to 12V transformer that fits. Old was 1.5VA or 125ma (0.125A) Any transformer 12V with that much current, or more will do.

Some have taken a regular panel mount transformer can wired it over to the pins on the board.