Hi All.

looking in to diagnosing the fault on the MC2100ELS-50W-V1 within our NordicTrack running machine and repairing. Switched on recently after a long time off and an audible fizz/pop from the controller board area plus a burning electrical smell so that’s why I’m starting there. This was when powering the machine up, not attempting to start a run.

I’ve started very basic fault finding and 240v is making it from the switch in to and out of the motor and to the controller.

I have a multi meter and soldering equipment and am keen to learn but also appreciate there is a lot of the basics in knowledge I do not have. I know I don’t know a lot. I also don’t know what I don’t know

That said keen to roll up my sleeves and learn more, even if it’s to check some basics that will then help me understand whether it’s within my reach to repair, needs sending to someone who can, or just needs the entire board swapped out (don’t want to be wasteful needlessly).

Here’s what I’ve observed so far.

1. 240v is reaching the controller board
2. The Red LED status light on the board which I believe normally blinks or stays on is permanently off and doesn’t light up at any point of powering up.
3. There looks to be a popped resistor on R3 (attached picture)

I’ve not progressed further than this yet and am looking for recommendations on what to look in to further. I’m guessing there are a number of parts on the AC to DC conversion part of the board that would be the first place to look?

Any advice appreciated - Thanks in advance. Phil

 

There is a reverse-engineered shematic in a past post search that covers a couple opf the few versions of the MC2100 boards.
But usually the main culprits are the semi's attached to the aluminum heat sink, it pays to check these first.
If you are getting HV DC then the 4 pin bridge rect is probablly OK. !

 

Thanks MaxHeadRoom.

I’ve pulled the board from machine to get a closer look at it. I’ll have a look in past threads but the schematics I found when I looked seem to be different versions/layouts. Have you seen one for this version?

I’ll look again. Let the fun begin

Phil.

There is a reverse-engineered shematic in a past post search that covers a couple opf the few versions of the MC2100 boards.
But usually the main culprits are the semi's attached to the aluminum heat sink, it pays to check these first.
If you are getting HV DC then the 4 pin bridge rect is probablly OK. !

 

I would check the large semi's mounted to the Alum frame, they are ususlly a power diode and Mosfet for the motor and a SCR for the elevate.
Check the LV DC, usually 12vdc, Bench testing is a little easier with a PWM signal into Pin 4 of HD2.

 

I think I’ve found the culprit .



I’ll need replace r3 too. It appears to be 2ohm but how do i know what wattage rating? Any other specifics useful for me to order the correct part?

 

Does this table help?

 

Thanks! Will give it a measure and see how it compares.

If anyone has replaced one recently would be interested to know what they swapped it for.

Does this table help?
View attachment 369128

 

Red-Blk-Silver
20Ω
20 Ohms

 

It’s red, black, gold, gold (from what I can see) with a black on the end?

Red-Blk-Silver
20Ω
20 Ohms

 

The STR-G6653 has a big crack in its casing and fails the few basic tests I’ve done. Hoping it’s hasn’t damaged things further along than it.

 

OK Red Blk Gold
Still 20 Ohms !

 

Its the low voltge DC source, a small switch mode PS, ~12vdc .

 

I’m struggling with this for various reasons (all very new to me)
The various codes I read none quite make sense with this colour combination.

For starters it appears to have 5 colour bands but doesn’t follow any of the conventions I’ve found for 5 band.

The 1st gold band (3 along in ). Isn’t that a 0.1 multiplier?

Red = 2
Black = 0
Gold = 0.1?
20x0.1 =2

or have I got that wrong?

OK Red Blk Gold
Still 20 Ohms !

 

Gold Silver is the tollerances.
the value only shows two colours.

 

Docs I’ve looked at also have gold as a 0.1 multiplier. Whys that incorrect in this case when it shows Red, Black, Gold , Gold, Black?

very new to this to trying to navigate how to decode the colours which seem a lot less than straight forward

Gold Silver is the tollerances.
the value only shows two colours.

 

This thread with the same board version and R3 blown seems to suggest 2ohm too with the same colour code.

https://forum.allaboutcircuits.com/threads/mc2100els-50w-v1-treadmill-repair-2.190797/

Docs I’ve looked at also have gold as a 0.1 multiplier. Whys that incorrect in this case when it shows Red, Black, Gold , Gold, Black?

very new to this to trying to navigate how to decode the colours which seem a lot less than straight forward

 

SORRY, I measured one I have here and it IS 2.0Ω !
My bad. !

 

Can we get an ID on U6 for the record?

 

For my specific board? (There seem to be quite a lot of variants right!)

U6 is here on mine, is this what you’re looking for? This is off my phone so I’ll go have a look at the board later and see if it has any numbering and update.

Can we get an ID on U6 for the record?

 

No problem. I’m fumbling my way through this so really appreciate all the help!

I’ve ordered new blown parts but will need to work out what else around them might have gone pop during whatever’s caused it.

SORRY, I measured one I have here and it IS 2.0Ω !
My bad. !