One of the conductors in the cord of my neck/shoulder massager has been cut.  I think the dog started chewing through it when he was a puppy and it recently completely broke.





My initial thought was to use wire nuts and some electrical tape, but that will create a "lump/bump" in the cord.  Maybe solder the wire back together? 

There is stitched closed zipper that should give access to where the wire connects to the motor, but I'd rather not mess with disassembling the whole massager to replace the entire cord.



Does anyone have any suggestions on how I can most easily (but safely) repair this? 

Thanks!

Thanks for the reply and the instructions.  I kinda thought that might be the proper way to fix it.

Does anyone have any recommendations for a soldering iron or ideally a kit that includes the soldering iron, solder, and shrink tubing?

I've never done any of the this type of soldering.  I've only had limited success soldering copper plumbing pipes.

Is patching a cord with this method ok with your electrical code? I would think it is only allowed for low voltage, not high voltage. 

Is it possible to access the end of the power cord inside the device. If so since the damage is so close to the end maybe just elect to lose those couple inches in the overall cord length and make the repair internal. That way no splices to worry about and nothing visible on the exterior to indicate it was ever repaired.

Without being able to see the termination of the power cord internally it's difficult to advise if this type repair is even possible, but it may be worth considering if it is possible to gain access to inside the device without damaging it.

If you are not comfortable with soldering then this type repair might be something left to someone with more experience but it shouldn't cost much to have a small appliance repair shop fix it. You could invest in the tools and learn to solder but in the end it may be cheaper (and a better quality repair) to let someone else do it.

The plastic, flexible device is a strain relief, it keeps any tugs on the cord from pulling on the connections inside the white plastic case. It looks to be a type that's molded onto the cord, there are other types that can slip onto the cord.
As mentioned, the best repair might be to shorten the cord to eliminate the damaged section and redo the connections inside the plastic case. If you're lucky there may be spade connectors inside, and you would just need to crimp new connectors onto the wires, so you'd need to buy a crimper instead of a soldering iron. Accessing the connections is likely possible by removing the screws that hold the white plastic shell together.

It's likely that the repair is simple, but if you don't have the tools and knowledge, it's not so simple anymore. Are there any small appliance repair shops or perhaps maker spaces near you where you could get it repaired, or perhaps get guidance and access to the needed tools (maker space)?

For a possible alternative if you want to tackle it yourself; There are two wire plugs and in-line outlets that don't require tools, if this device doesn't draw a lot of current, you could probably use those to make a plug connection that could nestle inside the cover. Any hardware store should carry them, you would put the outlet part on the long cord and the plug on the short piece of cord. This would more or less turn the long part of the cord into an extension cord with a very short power cord on the device.

You're kind of stuffed on this one because of the over-molded strain relief. The white flexible material is probably used to keep the soldered wire ends and the wire itself all vibrating at the same level & frequency. Because of the vibration, that would ensure a longer life for the connection.

As Bob D. suggested, If you don't have the tools needed this repair will not be free. 

You'll need a chisel point soldering iron in the 30-35 watt range.

Some rosin core solder, do NOT us flux core solder!

While not absolutely necessary, a soldering iron stand is a welcome accessory. When hot, the iron will be in the 450º to 475º range. Because of the form and the stiff electrical cord, the irons have been known to roll around on the table and burn wood, plastic and anything else they come in contact with. They also sometimes roll off the table and land on your leg (that really hurts) or on the carpet/floor.

If you purchase good quality tools, Ungar or Weller, you're probably looking at a $50-$75 purchase price. Ungar & Weller are owned by the same company. I'm sure there are cheaper alternatives out there but I'm unaware of what they are.

I'm going to show in pictures what Jiggy said in words.

Here's a photo of a 33 watt Ungar iron with a chisel point tip. This is what you'd use for your repair. The chisel point maximizes the amount of heat that goes into the solder connection.
Also shown is a 25 watt Weller with a needle point tip. It's used for LEDs.
A Weller soldering stand & a roll of resin core solder complete the photo. I think the solder alone was $20.
These hand irons are usually purchased in 3-pieces. The handle...the heating element...the solder tip. You choose each item.
The yellow sponge on the soldering stand is kept moist and is used to remove excess solder from the tip and to keep the tip clean for maximum heat generation.




Here's what Jiggy was talking about. Two small pieces of heat shrink, one for each solder connection and a single large piece to cover both solder connections. That produces a nice looking professional result.

The individual heat shrink pieces need to be some distance from each solder joint. The iron's putting out 450º but the heat shrink will start the shrinking process at 200º.  Put just enough heat into the solder joint to get a good connection, then remove the iron and cool down the joint by blowing on it. Slide the heat shrink over the solder joint and shrink the tubing. Then move to the next solder joint and repeat. Finally, shrink the large heat shrink over both solder joints.



A couple of final notes. Make sure the joint is cool before you slide the heat shrink over the connection. At times I've rushed the process and when I started to slide the heat shrink over the joint, there was still so much heat in the joint that the heat shrink tubing shrunk before I could slide it fully over the joint.

I prefer to offset the solder joints by 3/4"-1". There will be a slight bulge when the joints are soldered and covered with heat shrink. So 2 bulging connections next to each other produce a larger bulge in the finished product. Offset them slightly and the cord will be straighter and look better.

Let us know what path you decide to take. 

Whatever repair you use, make it outside the cover. If it is inside you won't be able to see it or know if it is working loose, not holding up, etc.

Soldering will give you the smallest "lump" comfort wise. But you cold also go with crimp connectors. Or even heat shrink crimp connectors. And put more heat shrink tube over those.  I have recently used adhesive heat shrink tubing. Which really helps keep things from coming apart and seals to the wires / cable.

Is that also a heating device?  What is the power draw?

Seth

Cheese has nailed it, this is exactly what I was describing. After seeing the further investigation, I would certainly use the solder method. The shrink tube will be more than adequate to insulate, and with a bit of care the massager will be as good as it’s always been, with just a piece of heat shrink giving the game away.

Do you have a friend that might possibly have the soldering kit, maybe they could do it for you too?
It’s handy to have soldering irons though, and getting comfortable using them. I have a few, the little gas ones are very handy I’ve found.

WOW! I am amazed so many people are saying to repair the cut. With the cover unzipped and access to the cord connection to the massager as shown, cut the cord at the damaged area, and re-attach it properly to the massager. The strain relief will most likely slide around on the cord and could be slide before cutting it. If not a spike slide around inside the strain relief should free it up. Not only will it not cost anything, but it will be repaired properly with no visible repair. The 6" loss of cord shouldn't be enough of a loss to matter. Either way a soldering iron will be needed although a nail heated with a torch would probably get the job done.

I have the Milwaukee M12 and like it more than my butane soldering irons, but a plug in with variable temps is better for board work. Few do that kind of work, and a soldering iron from Harbor Freight would do the trick.

Quote from: Peter_C on June 18, 2019, 01:29 PM

WOW! I am amazed so many people are saying to repair the cut. With the cover unzipped and access to the cord connection to the massager as shown, cut the cord at the damaged area, and re-attach it properly to the massager. The strain relief will most likely slide around on the cord and could be slide before cutting it.

The strain relief is the problem, it will probably not slide around because it also acts as pull protection. You must leave the pull protection intact at all times for safety.

You could of course make your own pull protection.

Also, soldering two wires together is quite a bit easier than soldering on a circuit board.

   This ^   Plus I am pretty sure that type of strain relief is molded with the cord.

   However I do think that a replacement of this type of cord could be found with a little internet searching. But that still leaves learning to solder for the first time on a circuit board. Soldering on the circuit board is why I would opt for the repair.

Seth

You're on the Festool Owner's Group. The only logical repair here is to do a plug-it conversion so that your massage chair is interchangeable with your track saw cord.

That would work well, except that (as I understand), the plug-it conversion is NAINA

Did you happen to try HoMEDICS for parts?

https://www.homedics.com/parts-and-accessories.html

I would have tried to look it up but they have a bunch of
different models and with the little info I have could not
determine which model you have.

But it couldn't hurt to try them.

Yes, they probably wouldn't want you playing around inside. Good point.

Thanks for all of the earlier replies with pictures, advice, suggestions, and feedback.  A local FOG member (with the required equipment) has offered to help me make the repair.

The strain relief is indeed part of the cord.  It cannot be moved.  I did a quick search earlier on Amazon, but couldn't find a similar cord.  I don't think I was searching for the correct terms - I was looking for "appliance cord with strain relief" but didn't have much luck.  Amazon probably isn't the best place to try to find something like this, though I don't know where I should be looking.

Good for you...the local FOG member is a great solution...arguably the best solution...he/she deserves a special mention & kudos. The over-molded strain relief will always be a nemesis as they're sized dictated upon wire conductor size and the appropriate housing hole size.  In this case, one size doesn't fit all and it never will.

Whoever the member is, that is a very nice gesture and a great example of what this site is about 

Agree, thanks to you whoever you are for helping a fellow member in need.

The cable could be cut at the damaged point, and an aftermarket pvc or nylon or even rubber gland could be fitted before re soldering. If the fit is a bit loose, a bit of hot melt or silicone to hold it firm.

Anyway, I’m sure whoever is doing the repair, will know the best course of action, once everything is in front of them.

Superb job, and fair play to the masked man!

To quote Shakespeare...All's well that ends well.