MC2100 treadmill motor control circuit #2

Thread Starter


Joined May 3, 2020
Hello all, any MC2100(E) experts still here? :)

I got asked to take a look at one treadmill that stopped working by a friend. From what I found power/control board blew.
It's MC2100E Rev C board. I tried looking for schematics, to see what all components are, with mixed results. I took a look at the one posted here, but I'm not sure if it's this exact model (it says MC2100, not E variant).

So far I found that these components got damaged: U5, Q5, R45 and R46 (plus one trace near D17 silkscreen).

Here are the images (there's lot of them so I uploaded them to separate site). I made pictures of few other parts that might be of interest to people here. Microcontroler (U3) looks like it also got damaged, but I think it's OK, stuff that looks like melted plastic seems to be some kind of lacquer, I scratched it off with my nail and etched letters remained).

- Schematics say U5 is MIC4227 but I haven't exactly found info on this part, only MIC4427, is this typo in schematic? I found relatively high res image of MC2100 board and I think it does say MIC4427.

- R45 measures as 1k7 Ohm, although from marking I managed to take a picture of it seems it says 30C which should be 20k Ohm. R46 is completely blown so no markings are visible. But I would guess it was the same as R45. Does anyone knows what values these should be?
R34 and R35 (marked as 102) on MC2100E are R29 and R30 on MC2100.MC2100 doesn't have these, or equivalent of these.

- Lastly Q5, I think Q2 is equivalent on MC2100 board, which is IRFP250 mosfet, is this correct for MC2100E? I've seen in this thread that IGBT APT30GT60BR was mentioned and part of the text that's still visible on Q5 on this unit begins with APT.

Hi, there is a board with a burnt out U5, but in my city it is difficult to get a MIC4427. Are there any analogues? I found somewhere on the forum that the IR2127 should work, but I'm not sure.

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Joined Jul 18, 2013
That is a high side driver, you may be able to use one of the other IR2xxx series of Mosfet drivers for this.
I believe they just use the MIC4427 as an interface for the micro output.