Treadmill board component burn repair

[Tansmile]

Hi
I hav treadmill board burned. There are 2 component burn out and i am looking for replace it.However, i am not sure what is the value of the components, can anyone expert advise here? Thanks in advance.

The 2 components labeled as RS1 and TH1 burned look like seramic caps. They are connected to rectifier KBPC3510N.

The treadmill board is KPT451Driver ver2.1 2008/12/13.

I need helps to identify the component RS1 and TH1 and thier values.

 

[danadak]

Cause has to be established. The large cap is bulging at top which suggests
it needs to be replace. That could have caused a short and taken out bridge,
square package with 4 lugs on it. I would also check power fets bolted to heat-
sink.

The disk shaped part probably a varistor or MOV, try to read the part labeling
on its side. Its a transient V protector for circuits.

Try to get a schematic for it and post that so forum can give you additional guidance
on what to check. Or hand draw one.

Regards, Dana.

 

[augustinetez]

Might be just the picture angle but that cap looks fine to me.

There is an earlier version of that pcb on Aliexpress but no clear shot of the values of the components.

I suspect the bridge rectifier is shorted which has taken out the MOV, possibly a cap and the fuse.

 

[Nigel Goodwin]

Might be just the picture angle but that cap looks fine to me.

Yes, from the picture it looks fine - and large capacitors like that one aren't really prone to bulging.

However, he's correct that it's VERY unlikely just to be the visibly blown components.

 

[danadak]

The large cap look like either of these ?

Also any of the smaller caps look like this -

The above all suspicious.


Regards, Dana.

 

[Tansmile]

Thank you for responce.
Yes, these burn mark having these 2 components burned. I think they are Ceramic caps, but i dont know the value.

If anyone experts in Rectifier design and can give a guess on these 2 components value. I tested the bulk caps is fine and the rectifiers also good..

 

[Tansmile]

The large cap look like either of these ?

View attachment 136020

View attachment 136022

Also any of the smaller caps look like this -

View attachment 136024

The above all suspicious.


Regards, Dana.

Ok.. will double check again

 

[danadak]

Thank you for responce.
Yes, these burn mark having these 2 components burned. I think they are Ceramic caps, but i dont know the value.

If anyone experts in Rectifier design and can give a guess on these 2 components value. I tested the bulk caps is fine and the rectifiers also good..

I think those are MOVs, not ceramic caps......

How are you testing the caps ?

 

[Tansmile]

I think those are MOVs, not ceramic caps......

Oh IC..

 

[Nigel Goodwin]

I think those are MOVs, not ceramic caps......

I would agree, they don't look like caps, but do look like MOV's or similar.

 

[MaxHeadRoom78]

TH1 would indicate a Thermistor.

 

[Tansmile]

Try my best to draw part of the schematic from the circuit board.

 

[rjenkinsgb]

I suspect either TH1 or RS1 is in series with the input to the bridge rectifier, as an inrush current limiter?

 

[Nigel Goodwin]

I suspect either TH1 or RS1 is in series with the input to the bridge rectifier, as an inrush current limiter?

I would agree, most likely one across the input to the bridge, and one in series with it as an inrush limiter - no point in two in series across the bridge.

 

[klody_1977]

Hi everyone, I have the same problem the 2 ceramic capacitors have exploded, you can read something but I'm not an expert, if someone can help.

as soon as I can I try to unsolder it and post a better photo.

 

[Nigel Goodwin]

It's not a capacitor, it's a thermistor (TH1) and RS1 is most probably OK, just a bit scorched from the demise of TH1.

 

[klody_1977]

Thanks, so it could be one of them

I am a mechanic not an electronic.
Maybe you could advise me which one