Telwin Mastermig 180 problem

[Tengtooltom]

Today I put on a new bottle of Argon Light and a new roll of 0.8 wire on my Telwin mastermig 180 and Nothing Happens!!! The machine was in storage for the last couple of years - it was purchased new by us in 1990 and used for general work up to a few years ago. I stored it since and tried it out about six weeks ago with a little roll of ALDI gasless wire. I only had it plugged into a kitchen socket. It welded ok for about 20seconds and tripped the fuse/RCB. I gave up at that stage and got a proper 16a socket installed into my shed. Today I started as above - new wire and new gas. The fan runs, it feeds the wire but not sure about the gas . But no arc, even if I connect direct to the earth clamp. I have removed all of the covers and checked the little fuse on the PCB - ok. The little red light on the front panel in on - ok. HELP!

 

[malcolm]

What does the red light do? Is it a power on (OK) light or a fault (overheating or something broken) light?

Well worth turning it off and flipping all the switches on the front backwards and forwards for a start - they can get stuck or dirty.

 

[Tengtooltom]

What does the red light do? Is it a power on (OK) light or a fault (overheating or something broken) light?

Well worth turning it off and flipping all the switches on the front backwards and forwards for a start - they can get stuck or dirty.

The light is power on - there is a fuse beside it. If I remove thes fure the light goes off and the fan stops.
Could it be anything to do with old dirty/rusty wire? The liner is a metal coiled spring type and is the original one. It was pulled back out towards the feed roller by about 10mm. I pushed it back in and tightened the little grub screw.
I also opened up the gun - everything looks ok in there? When I press the trigger the switch inside the machine engages and the wire feeds.

 

[Tengtooltom]

I found this photo on the Forum "telwin" by "the Priest" 25/10/2006.
This is the same make and model as my machine Mastermig 201!

 

[malcolm]

The wire liner should extend as close to the rollers as possible - otherwise the wire birdsnest.

Have you tried more than one power setting? If it works on one not another it could be dirty switches or connections to the switches. If it's been sitting for a while possibly dirty connections in the main cables to earth or torch.

Another thing to check would be the rectifier (2 aluminium plates with diodes pressed into them). Have a close look using a lamp for any smoke marks near the diodes. Those would trip an rcd if they blew, but I would have thought you would have needed to blow more than one to stop the welder from arcing.

 

[Tengtooltom]

Ok, I have just found the problem!!! and maybe the reason why!!!
The switch (dont know its proper name) that actually moves (clicks) when the trigger is pressed is burnt out on one pair of contacts. It is a big contactor type switch, similar to the inside of a start/stop switch. It has a spare set of contacts next to the burnt out ones. can I use these???
The mains lead coming into the machine is connected up as follows:
Green/yellow to the earth symbol
Brown to the "N" symbol
Blue to the "R" symbol
Is this correct?? "N" in my opinion is neutral and should be the blue wire. I have not seen "R" before but should it be brown/live. As far as I know it has been always this way!

 

[rgcamillo]

The wire liner should extend as close to the rollers as possible - otherwise the wire birdsnest.

Have you tried more than one power setting? If it works on one not another it could be dirty switches or connections to the switches. If it's been sitting for a while possibly dirty connections in the main cables to earth or torch.

Another thing to check would be the rectifier (2 aluminium plates with diodes pressed into them). Have a close look using a lamp for any smoke marks near the diodes. Those would trip an rcd if they blew, but I would have thought you would have needed to blow more than one to stop the welder from arcing.

I am currently repairing the telwin bimax 162 and there is no arc on them. I tried to locate what is wrong but until now i cannot find because when i start repairing this the 2 plate that you mention was already remove by my co worker and dont know how to return it. what is RCD that you mention ..please help..are thse diode just ordinary and can be check with volmeter?