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Jon Elson[_2_] Jon Elson[_2_] is offline
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Default Miller Syncrowave 250DX welder Amperage problem



Eug wrote:
This machine is a 2004 model used for tig with a water cooled torch
and foot pedal remote control. The problem started when the remote
cable was damaged causing the machine to give an error code 12. The
foot pedal cable was repaired and the machine now starts up normally.
Now I can strike an arc but cannot get the machine to go over 56 amps.
The foot pedal appears to control the amperage but maxes out at 56,
even with the front panel amperage control set to max. The amperage
indicator reads up to 310 amps when idling but while welding, never
goes over 56.
To try and isolate the problem, I switched to “panel” control of
amperage and in this condition full amperage is delivered. Since we
have other machines in the shop, I swapped in another pedal resulting
in the same problem. (And the first pedal works fine on the other
machine.)
My guess is only two things remain, either the wiring from the plug to
the mother board or the motherboard itself.
I am hoping someone can suggest other tests or possibilities
Thanks!
Eug


The main box sends a current through the pot in the foot control, and
senses the voltage on the slider. There is most likely a resistor on a
board in the main box in series with the pot in the foot control, and
the shorted cable has burned up that resistor. Open the machine and
examine the boards for a burned part. You may need to trace the wires
from the foot control plug back to find the burned part. (It is
possible that the component's value has changed, but the part is not
totally charred to a crisp.) If you can find a burned component, check
one of the other machines to be able to read the part value, and
replace. With just a little luck, you should be able to fix this for
under $1.

Jon