# Controller, MC2100-12A transformer

#### JJJ35

Joined Jun 8, 2021
22
i have a treadmill PCB/Motor control board. The Yellow transformer was burnt out. Can i but just the transformer and solder back to the board and keep from having to buy the entire circuit board? If so, where do i find if? Anyone know the exact part number? It fits a proform xp 542e if that helps in anyway.

Controller, MC2100-12A

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Joined Jul 18, 2013
24,971
What makes you sure the transformer has burnt out?
It just simple provides the LV for the board and console, Usually 12vdc for the HD2 supply and 78L05 5v regulator.
Vary rare for the transformer to fail, there may still be a reason that requires solving before replacement.

#### JJJ35

Joined Jun 8, 2021
22
so older house had a massive power surge. everything in the back bedroom was burned up. Tv, ceiling fan light bulb, closet light bulbs etc… i took the PCB out and the top part of the transformer is black where it looks to be burned up.

#### JJJ35

Joined Jun 8, 2021
22
LED on the circuit board lights up still. I read on some site that this light shows that the board has power, just not enough power to send power to the upper mother board. im told the lower pcb is the motor control board to om the treadmill.

Joined Jul 18, 2013
24,971
Is this used on a 230v or 120v service?
Although transformers of the voltage are numerous, it may be difficult to find one with the exact PCCT footprint.
One way is to mimic the older version that had the transformer off-board.
The Status LED and the micro-processor has it supply separate to the console which takes the supply from the transformer for isolation from the mains.

#### JJJ35

Joined Jun 8, 2021
22
i believe its just 120v. simply plugs into a regular wall outlet. Its not a commercial series treadmill. Just a consumer treadmill bought at sears years back. Just curious if i could simply buy and solder a new transformer on it without having to buy the entire 350$circuit board. the treadmill itself was 675$ new.

Joined Jul 18, 2013
24,971
Like I said, if you do not want to go the difficult route of finding an exact PCT replacement, there should be room to fit an external, just requires two for the primary and two to the 12vAC, I have one on the bench, I could measure the exact secondary, if you wish.
I f you want to look for a PCB version, DigiKey has many, you need the same approximate frame (lamination dimensions).

#### JJJ35

Joined Jun 8, 2021
22
i know nothing about electricity or circuit boards. this is all new to me. I understand some of what your talking about. I appreciate the feedback.

Joined Jul 18, 2013
24,971
It seems you were able to remove the old one, so how did you want to proceed?
I could check out the Digikey site for drop-in replacement, but it may be a stretch to find one with the same footprint.
If this is the case, then if there is room, the external one would be the easiest option, older versions use this.
If you removed the old one, presumably you can solder leads into the board from the new one.
But like I said, it pays to find out why it failed in the first place, otherwise the fault is likely to repeat itself.

#### JJJ35

Joined Jun 8, 2021
22
the cause was a major power serge in my grand parents old house. Problem was fixed by an electrician.
If you could find out if they have an external that would be great. What info you need from me? It will be a day or two before i get back over there to get the transformer for any info you might need from it.

#### JJJ35

Joined Jun 8, 2021
22
i do have the circuit board on hand that i could get measurements if needed.

Joined Jul 18, 2013
24,971
I have the info for the transformer.
BTW, I would also check the large capacitor on the other end of the board, where the rectifier diodes are, it is rated very close to the actual LV voltage, I always replace it with a higher voltage version.

Joined Jul 18, 2013
24,971
Incidentally, how did you unsolder the old transformer?
The board doesn't seem to have been removed from the heat sink chassis. !

#### JJJ35

Joined Jun 8, 2021
22
i heated it with a solder iron. Used cooper fiber to remove solder and lifted it free from the board.

is that the capacitor your referring to? i believe its 16v if thats what your talking about.

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Joined Jul 18, 2013
24,971
Yes, the 16v one, it is sized, voltage wise, too close to the actual voltage, and sometimes can exceed it if the transformer 120v supply is a little high.

#### JJJ35

Joined Jun 8, 2021
22
so replace it to?

Joined Jul 18, 2013
24,971
I would!

#### JJJ35

Joined Jun 8, 2021
22
so what do you recommend volts to replace with?

Joined Jul 18, 2013
24,971
24vdc min.