Proform 320cx PCB component identification and repair

Thread Starter

LoocPac

Joined Dec 21, 2019
2
I found a Proform 320cx on the side of the road in what seemed like great condition. got a replacement power supply and plugged it in to find out there was an issue. I disassembled the main controller and found 1 component burned. A small black block labeled DP 2. I searched online to just find a replacement board, but all I can find is a replacement for the entire device, which is several hundred dollars and not worth it.
Unfortunately I can not see any markings on the component, which is why I am here. Where the component was is charred, but the traces on the reverse side seem fine, so if i can identify the component I should be able to connect it directly to the trades after a little work and some resin to repair the board.
Please see attached photos, any help would be great. I am still learning components so without markings I am a bit lost.
 

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MisterBill2

Joined Jan 23, 2018
9,851
If that object is DP2, then it seems that there should be a dp1 some place on the board, and if it is not burned up you may find a number on it. The label is an indication of what circuit drawing component it is, not a part or model number. It may be that youi will need to locate a circuit drawing to get the information that you need. And it may be that tracing out thwe circuit will let you know what the part was. DP2 may be short for "diode , protective, 2"
And one additional thing is that to burn up a component that completely takes a bit of power. Usually parts do not just burn up for no reason. So either the voltage across the part suddenly became far too much, or the current through the part became too much. So there is probably a short circuited component that caused the part to fail. For that you need to be able to trace the circuit and see what components couldcause the failure.
 
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Thread Starter

LoocPac

Joined Dec 21, 2019
2
i was able to find a number under the burn with a really strong light and some magnification, i believe it was an M1 diode. i will go through the rest of the board and look closer under magnification to see if there is anything shorting or anything else that looks damaged. thank you for the response.
 

pmd34

Joined Feb 22, 2014
520
I think MisterBill is spot on really.. it might be worth trying to trace where the connections to the component go, if its pretty much direct to the connectors, then there is a reasonable chance that it was some external plugged in part that blew the component and the circuit might have been saved from damage by the component blowing.
 

MisterBill2

Joined Jan 23, 2018
9,851
Power diodes almost never fail for "no reason", and so certainly you need to do some searching and inspection. I am guessing that the whole thing is a treadmill of some flavor, and in that case there may be some variety of intermittent short circuit in some of the wiring, such as a pinched wire. What is certain is that a whole lot more inspection is required. If you do get another diode it would be a good plan to add connections to put a 100watt lightbulb in series with it for the initial try-out. That will save the diode in the event that there is still a short circuit or a large overload.
 
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