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Welder, SUPER-200P Upper Board's - Field Tube Inverter Board, repair or replace?

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Newbie level 4
Apr 29, 2022
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My Chinese made (SUPER-200P model) welder’s field tube inverter board got fried. I need help identifying a replacement for it. Problem is that the welder has no schematic and it is analog and older. Also, the transformer on it is labeled as Ei28 15:7, and all other replacement boards now have Ei28 series transformers labeled as Ei2816:8. What is the difference of 15:7 and 16:8, and is it significant or can they be compatible swaps?

The parts which burned on my inverter board are:
  • The Ei28 15:7 transformer.
  • (2) correcting capacitors labeled as part 220nJ100.
  • A Zener Diode marked as 1N48 series, with a “C2”. (I have not yet tested the voltage of the other good "C2" Zener diode on the board).
  • A 3K 1/4W +/-1% resistor
Some of the replacement inverter boards I found on aliexpress have PCB markings next to the Zener diodes. Those boards use either 3v3 or 5v1 Zeners. (I have NOT yet tested the ones on my board yet. I am waiting for a variable DC-DC power supply regulator I have ordered.) All replacement inverter boards are showing their correcting capacitors to be 224J100. Can anyone tell me if that is ok to swap with a 220nJ100, and are they sharing the same specs?

Any of the Ei28 transformer I have found all have two leads, which connect directly to the Welder’s front face controller panel. It appears every Chinese welder replacement upper board, shows output of 24V to the front face controller panel. I do not know the voltage that came from my inverter board before it was fried and I am assuming it is the same 24v. Does anyone have knowledge if the Chinese made WELDER circa 2005, replacement inverter boards, are all similar output voltage of 24V, for the SUPER-200P model welder?

Please help me with my strategy. My solution, is to go to aliexpress and find either a replacement inverter board, or a replacement Upper Board that has an inverter board. I am thinking I should get one that has the Ei28 16:8 transformer, and just make certain it has the same dimension of the 8 solder pin out locations and the board measures the same as mine, 66mmX30mm, and just swap them.

Could that work?

Thank you.

I'd say to get a replacement board (if you can verify it really is)
and "reverse engineer" it to aid in repairing the burnt one. If
it blew up once, it'll blow up again most likely and you'll have
a space on hand.

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