no Idea how it detached I know where it fits the tangs are still in place I tried the mig it powers up but does not arc, opened side panel and found it In the bottom.

I wouldn't reattach it if you can find the replacement. I'm looking over the schematic now.


kv

 

no Idea how it detached I know where it fits the tangs are still in place I tried the mig it powers up but does not arc, opened side panel and found it In the bottom.

What is the resistor labeled? Single Phase or Three Phase.

kv

 

no Idea how it detached I know where it fits the tangs are still in place I tried the mig it powers up but does not arc, opened side panel and found it In the bottom.

Usually cause by poor connection offering resistance = heat.
If you can clean all connections thoroughly first in order to make good connection, with plenty of solder flow, it should be OK for a while.
There is obviously a fair current running through that part of the circuit as it is.
Max.

 

Usually cause by poor connection offering resistance = heat.
If you can clean all connections thoroughly first in order to make good connection, with plenty of solder flow, it should be OK for a while.
There is obviously a fair current running through that part of the circuit as it is.
Max.

I found this one looks like the N38-20 might mean 20 watt. This one is 20 ohm 25 watt 10%

https://www.mouser.com/ProductDetail/Ohmite/D25K20RE?qs=sGAEpiMZZMtlubZbdhIBIO0G6VCMyNyNl2MPXkpRxkM=

kv

 

I found this one looks like the N38-20 might mean 20 watt. This one is 20 ohm 25 watt 10%

https://www.mouser.com/ProductDetail/Ohmite/D25K20RE?qs=sGAEpiMZZMtlubZbdhIBIO0G6VCMyNyNl2MPXkpRxkM=

kv

The resistor actually says "5%" on it. From the look of it, it could be anywhere from 20 to 50W.

 

The resistor actually says "5%" on it. From the look of it, it could be anywhere from 20 to 50W.

I'm also questioning if that resistor is partially shorted since you can clearly see 200m ± 5%

kv

 

It is certainly not 200meg at that wattage!
I always tend to use the type with a radial screw mount and use metallic stand offs with screw from the PCT board, rather than solder termination.
This range from Digiky may have it, definately LOOKs like 20Ω
https://www.digikey.ca/product-deta...ctric-inc/FVT05006E25R00JE/FVT50-25-ND/257596
Max.

 

e

It is certainly not 200meg at that wattage!
I always tend to use the type with a radial screw mount and use metallic stand offs from the PCT board, rather than solder termination.
This range from Digiky may have it, definately LOOKs like 20Ω
https://www.digikey.ca/product-deta...ctric-inc/FVT05006E25R00JE/FVT50-25-ND/257596
Max.

The schematic is so bad you can't see what most of the values are. Be nice to see a better schematic.


kv

 

Found these, they would qualify also.

https://www.ohmite.com/assets/docs/res_200.pdf

kv

 

I have found a link to a copy of the schematic which is readable. This is the link. I have not yet found the resistor on the schematic. NOTE The red download text that you have to click on does not appear straight away. (It takes several tens of seconds.)

Gary, Can you tell us where this resistor was located ? ( On the circuit board (If so what is the component designation ?), or some other place in the welder. ) Does the main contactor pull in when the trigger is pressed ?

Les.

 

Powers up and feeds wire but no arc? Sounds like the broken link in the chain. Replace the component and I bet it will work. Won't bet much, I can't afford to lose too much, but I'm willing to bet a buck. (not really)

 

If a resistor that size is not supported and there is some lead length then it can vibrate and the copper conductors break. I had to repair a quite expensive multi-speed shop fan with that exact problem. The resistor lead simply broke. So at this point , having seen the photos, I would say it is 2 ohms. But still it needs to be replaced and for that a location is required and that will take a person who understands what they are looking for to find. And if the TS has no clue it will be a big challenge to find the spot where the green thing is not.

 

This is the method I use and never had a case of failure yet.
The board and the trace connection could probably be modified in the instance to a stand-off mount.
Max.

 

Can we get some pictures of the insides of the welder, particularly where the part fell off? From the low resolution schematic available (without a parts list), it looks like it might be R1. But if it is, R1 missing should not make the unit inoperative. As was asked above, does it sound like the main contactor pulls in when you pull the trigger?

 

Here is a more direct link to the schematic than the one I gave in post #50
http://murexwelding.co.uk/manuals/Tradesmig%20135-165-235-245-285.pdf

I agree with Ylli's theory that it is most probably R1. I think it will be mounted between two terminals of the main contactor. (I think it's value will be 20 ohms.)

Les.

 

What is the resistor labeled? Single Phase or Three Phase.

kv

Single phase

 

Can we get some pictures of the insides of the welder, particularly where the part fell off? From the low resolution schematic available (without a parts list), it looks like it might be R1. But if it is, R1 missing should not make the unit inoperative. As was asked above, does it sound like the main contactor pulls in when you pull the trigger?

Placed the resister where it came from it does sound like it pulls in sounds like it did before it stopped working

 

It’s vibration that cause it to fall off. Who know the welder may have dropped at some point. That is a huge rectifier.

 

Can we get some pictures of the insides of the welder, particularly where the part fell off? From the low resolution schematic available (without a parts list), it looks like it might be R1. But if it is, R1 missing should not make the unit inoperative. As was asked above, does it sound like the main contactor pulls in when you pull the trigger?

Just checked main contractor does not pull in

 

Contactor