Problem with Snap-On Pro MIG 2000

[51coupe]

I've had this machine for 2-3 years now and has been ok. Just recently I've had some wire feed issues.

Firstly
The wire reel turns freely
Liner is clear and good order

When switched on the wire feed seems relatively normal for the first 30 seconds of welding but the the motor speed starts to taper off. If you adjust the wire feed on the machine it improves but this is only temporary. Eventually it seems to settle down and functions with virtually maximum wire feed control showing(although in reality this is just 25% wire feed).
When you turn the machine off it clears itself and then the whole process starts again.
Also, with the wire feed rollers disconnected the same thing happens.

Yes it does function but I need to resolve this.

I am presuming this is a board related issue, as a component warms up it breaks down causing an increased resistance in the wire control circuit.

Any ideas as where to start looking on the board?

Dave

 

[NotANormalCoder]

I agree that this sounds like component breakdown on the pcb but it is also possible that it could be a fault with the main rectifier - some snap-ons are made by Cebora and take the feed for the motor supply from a take-off on the main rectifier. If plates of recifier are held together by one vertical bolt and there's a seperate but smaller top plate, try checking all connections and tighten central bolt as they loosen over time.
Otherwise, seizing motor? loose pcb connections/dry joints? If all else fails, pcb need a fix by a pro.
Good luck
Other Dave