No amperage adjustment with pedal

[esoto56]

Hello guys.

I have a syncrowave 250 with serial number starting with JJ. The unit was built in 1988, based off the serial number.

When I use the remote pedal, it acts like a start/stop switch with no amperage adjustment ability. More specifically, when I put the torch near the part it arcs but very little, almost like it’s giving me the lowest amperage and when I press the pedal, I get the maximum amperage that I have it set to. Nothing in between. . I’ve read a threads stating that it’s the PC1 but also that some guys have fixed it on their own by replacing a component. The board that is currently in it is part number 138307, the updated part number is 180014.

Any and all advice is welcome.

[ryanjones2150]

Test the pedal first before you do open heart surgery on the machine, I’d think at least.

[Aeronca41]

First thing we need is the rest of the serial number to be able to look at the right diagrams. There is a start stop switch in the pedal, but once it's on, the pedal obviously is supposed to control the current. Could be a bad pedal, broken wire, or some electronic/electrical failure inside the machine. I'll try to take a look at the diagram and provide some troubleshooting ideas once I can see the right schematic.

What is the model number of your foot pedal? I found a reference to a Sync 250 using the RFCS-14, but I'm not sure a machine of that age has a 14-pin plug--I think it might be a 5-pin?

[esoto56]

First thing we need is the rest of the serial number to be able to look at the right diagrams. There is a start stop switch in the pedal, but once it's on, the pedal obviously is supposed to control the current. Could be a bad pedal, broken wire, or some electronic/electrical failure inside the machine. I'll try to take a look at the diagram and provide some troubleshooting ideas once I can see the right schematic.

What is the model number of your foot pedal? I found a reference to a Sync 250 using the RFCS-14, but I'm not sure a machine of that age has a 14-pin plug--I think it might be a 5-pin?

The pedal is brand new, just bought it at my local weld shop. It’s not a miller brand, I’ll have to see what brand it is and i have the 5 pin remote plug. The whole serial number is JJ456722

[pat h]

Put the amperage control toggle in the Remote position you have it on panel

[Aeronca41]

Put the amperage control toggle in the Remote position you have it on panel

Good catch. Hope that's his problem!

[esoto56]

That picture is when I first got the machine. It is set on remote.

[esoto56]

Is it worth spending another $700 or so on this machine? Should I sell it and purchase a new foreign machine?

[Aeronca41]

I really can't imagine this will cost anywhere near $700 if you can do some guided troubleshooting. It's possible, but there are a lot of cheaper things to look at first. My plan is always look at the cheap stuff first. Has this machine ever worked right with the pedal? Is it just since the new pedal, or is this the first pedal you've tried on it? What is the brand and model of your new pedal? I'm hoping to find some $50 or less fix here.

As near as I can tell from the manuals I looked at, that welder originally used an RFCS-23 foot pedal. If that is correct, then you should be able to disconnect the pedal from the machine, put an ohmmeter between pins C and E of the plug on the cable from the pedal, and read between 0 and 1000 ohms as you push the pedal from fully up to fully down. Then, connect an ohmmeter between pins A and B. With the pedal up, it should read infinite/OL. As soon as the pedal starts down, you should read 0 or close to it. That is the switch that tells the welder you've pushed the pedal. Let's verify that stuff first, then we'll move on to the welder.

[pat h]

It's a pretty common machine and way better than the later 250 dx machines, gotta be someone to help you out local repair shop or someone with a known good pedal

[ryanjones2150]

Of that thing used an rfcs-23 foot pedal, then you probably need to try an rfcs-23 foot pedal on it. I can’t say for sure about that foot pedal, but the rfc-23a on my old machine is very specific, uses a different type of mechanism, as I understand it uses higher resistance components than most others around. Not cheap, of course, and not easy to find good used ones. You can get new ones but they cost your arm and half your soul.

[Aeronca41]

RFCS-23 is a different animal than the -A version.

[ryanjones2150]

That’s good fortune then. Probably a lot cheaper too. He also said it’s an after market pedal, so maybe it’s plug is wired wrong. Worth a look see peek.

[Aeronca41]

Yep, I figured we need to know that's right before digging any further. Wouldn't be the first time something that was "supposed to work on your machine" didn't.