Soldering treadmillís circuit board


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Old 04-02-21, 02:39 PM
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Soldering treadmillís circuit board

Hi folks, Hoping you could give some advice regarding a broken peace on my treadmillĎs circuit board. As you can see in the picture, thereís a female connector that gets soldered to the board and thatís where the display cable plugs in. Itís an eight wire connector and looks similar to an ethernet cable sort of. When I opened up the treadmill and looked, the connector was no longer soldered to the board. Iíve soldered things before, but nothing to a circuit board this tight before. When you look at the board, it looks like the metal is partially missing where this connector would solder on. Do I still have the ability to solder the connector to the board?

Thanks!


The red arrow is where the connector should be soldered to the board.




 
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Old 04-10-21, 11:24 AM
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Thanks for all the input folks. Read all your suggestions and watches the videos online a few times. Then I gave it a shot this morning and it worked! I soldered 8 wires to the circuit board. And then instead of using that busted female port, I just took the cable from the treadmill that would plug into it, snipped off the mail connector, and attached the 8 wires from the treadmill to the new 8 wires on the circuit board and wahoo! Thanks again for all the help. Now I just have to actually USE the treadmill 😬




 
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Old 04-02-21, 04:09 PM
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Do I still have the ability to solder the connector to the board?
Yes.... but it's not going to be easy.

You'll need to clean the solder and old copper off the pins.
You will need to fasten the jack to the board. I use hot glue.
You will only be able to directly solder the bottom pin to the board.
You'll need jumpers from the other pins to where the foils broke.
I use #26 bare and insulated for repairs like that.
 
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Old 04-02-21, 04:48 PM
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Thanks for the reply. Are you saying I can only solder the bottom pin directly to the board because of space constraints? Do you have a link to what jumpers look like?
 
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Old 04-02-21, 05:01 PM
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He might mean because that's the one with the most contact remaining. The others really don't have much to work with and certainly not enough to help structurally hold the connector in place.

Jumpers are just pieces of wire. Since many of those contacts are now gone you need so solder a piece of wire onto each lead of the connector and solder the other end to some other point on the board. I follow the trace (the line on the circuit board) until there is a component that is soldered since it makes an easy place to attach the other end of the wire.
 
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Old 04-02-21, 05:13 PM
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You lost most of the foil off the board. It's stuck with solder on the jack. When you put the jack on the board the bottom pin is the only place where you can solder the pin to the board because it's the only full size trace left. You'll need to jumper from each of the other pins to a good trace. I have rolls of small wire. You can use the leads from resistors or some spare solid wire out of an old radio.

Jack repair on board video
Trace repair video
 
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Old 04-10-21, 07:19 AM
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The original fastening of that jack to the board was in the form of eight thin strips of copper foil glued to the board and the eight contacts on the jack soldered to those 8 copper strips.

The electrical connections from the jack to the board circuitry was via the eight thin strips of copper.

You have to refasten the jack to the board using other means, suggested was glue that will both stick to the board where strip ends are now missing (torn off) and also stick to the underside of the jack. The single strip still there is not strong enough to hold the entire jack in place.

Then you have to remake the 8 electrical connections using the #26 or thinner wire jumpers.(think: pigtails) you cut yourself. You can scrape off the varnish anywhere along the correct respective metal strip (trace) coming out from under where the jack was fastened and solder the end of the jumper wire there.

It would be easier to follow the strip to the next component since the strip gets wider to form a solder spot to the next component because it would be physically easier to solder your jumper wire to that solder spot.

A common problem with circuit board repair is a blob of solder too large it spills over to the next copper strip and causes a short circuit. In some factories workers use microscopes when soldering jumper wires to the copper strips on the boards.
 

Last edited by AllanJ; 04-10-21 at 07:40 AM.
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Old 04-10-21, 08:08 AM
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You might try looking for a replacement CB before going through all that work. Contact the manufacture or look on e-BAY.
 
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Old 04-10-21, 02:41 PM
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Not bad. You did a pretty good job. Looks clean and neat.
Add some type of wire restraint to keep the wires from bending and vibrating loose.
You could use a little dab of hot glue on each connection.
 
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Old 04-10-21, 06:24 PM
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Thanks! Are you talking about putting a dab of hot glue on the solder connection? Or do you mean gluing the wires to the board right before the connection as a strain relief?
 
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Old 04-11-21, 06:11 AM
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Either or. I've seen both.__________________________
 
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Old 04-11-21, 09:34 PM
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Either place. I'd put a drop right on each connection.
 
 

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