Thanks again! Removed the 4 screen from the heat sink and the one screw from the ground wire.

I don't see a plastic stand-off - but it comes off and goes on just fine now. Do I need any sealant or will it be fine without any and just the 4 heat-sink screws?

I really appreciate your help! Now to get it fixed and get back to running indoors. Too cold to run outside in Toronto the last couple of weeks!

 

Heat sink compound is an option, but it is not usually used on the original.

Colder here in MB!

 

You can test the board before replacing and before connecting the motor to see if any thing 'blows', the red LED should light steady.
Just connect the AC input.

 

Hi @MaxHeadRoom - Thanks for all your help.

I got the part today from Sayal (they only had a 2.2 ohm 2 watt). Got a friend to solder it on and installed the board back. Red light was solid when plugged it and all looked ok. However, as soon as I started the treadmill (only on speed 1), the same part started smoking and burnt.

So, I'm back at square one now. No idea what else to check for that could be causing this resistor to burn out. Any suggestions?

Don't want to throw out the treadmill yet, unless it's not worth repairing.

Thanks!

 

I believe on that model it supply's the 5 lead G5551 semi on the heats sink, often this goes shorted also check the D1 dide rect.

 

I believe on that model it supply's the 5 lead G5551 semi on the heats sink, often this goes shorted also check the D1 dide rect.

Way beyond my skills. Have no idea on how to do that or what those are.

 

They are a bit of an oddball IC, I think that ver is now obsolete, although some are still selling them.
You may be able to pick up a spare board, ebay etc.

 

They are a bit of an oddball IC, I think that ver is now obsolete, although some are still selling them.
You may be able to pick up a spare board, ebay etc.

Maybe time to just ditch it and buy a new treadmill

 

Is there a schematic diagram for this board? I friend said he could help diagnose if we have the diagram.

 

There is for the more common models, but I have not come across one for the MC2100LS-30.
The others do not use this IC.
They can be reverse engineered by removing the board.

 

What's the part for D1 please?

 

It has a cryptic 'S1J' on it, it would be the SMT equivalent of a 1n4007.

 

It has a cryptic 'S1J' on it, it would be the SMT equivalent of a 1n4007.

It has a GS1J - So maybe this one?

https://www.digikey.ca/en/products/detail/micro-commercial-co/GS1J-LTP/2213580

 

Looks like it would do the trick!
The G5551 IC/Mosfet on the HS is also suspect

 

Looks like it would do the trick!
The G5551 IC/Mosfet on the HS is also suspect

Please can I get a link for that part too in case I need it? Thanks!

 

I can only find a link on ebay for them, I have contacted the manuf. to see if the Later G5623 is equivalent.

 

I believe this model has used the G5551 and transformer as a SMPS, which is not the norm for the MC2100 series, in the past they have used a simple mains transformer and bridge or dual diodes for a LV 12vdc supply.
They have various editions of the simple transformer type, When I get the chance, I intend reverse-engineering the SMPS version and come up with a simple linear type, if necessary.
The supply is basically an isolated 12vdc supply to feed the console and its various controls.
One could be made up off-board if need be.

 

Can this be used in place of the surface mount diode GS1J?

https://secure.sayal.com/STORE2/View_SHOP.php?SKU=147483

 

Can this be used in place of the surface mount diode GS1J?

Yes, just that it is not as secure as the SMT version.
You could always drop a dap of RTV/silicone on it once it is working OK.
Incidentally I contacted the manuf. of the G5551 and the later IC;s and they say they do not manuf. them anymore, so ebay is the only recourse.
Also I am in the process of reverse-engineering the LV SMPS supply, it should be easy to replace it with a wall wart version quite easily.
Turns out the isolated DC supply on this version is 14VDC.

 

Thank you so much!