I have this MagicShine headlight, about 4 years old, been great. However now the wire, right where it meets the plug (to the battery) is frayed and
broken/separated from the plug. For a while electrical tape was doing the job but now I can't get power to the light at all.
Any idea how to fix? I was thinking of just cutting the wire and getting a new plug but not sure where to look for one or even if that idea would work.
Thanks for any help. Eric

You can either get an extension cable and chop it or you can short leads at dx.com.

If in a hurry get a cable from action or email them to see if they have a lead.
Action-LED-Lights ? 1m Extension Cable

Yeah. That's called a coaxial power connector and you need to match the outside and inside diameter. Of course you need to get the polarity correct when you install it. There's a decent chance you can find what you need at a Radio Shack. Like snomit said, you can get a new connector or get a cord with a connector already installed and splice it to your existing cord...observing the proper polarity. To get the polarity correct you need to know which wire in your cord goes the center and which to the outer portion of the connector and ensure the same is happening after you replace the connector or splice on a new one.

I would mesure the outside diameter with calipers and the inside using gauge pins or drill bits. You might be able to use the caliper to measure the ID of the plug (OD of the pin) if you can get to it.

Thanks, I think I'll go with chopping and splicing in with a new extension cable.

I don't know what 'short leads' means. Is the lead the very end of the cable without the rubber/plastic casing?

Cool. If I can't find anyone around town who carries an extension cable I'll try Radio Shack for the connector.. Thanks for the info and the tip. I would like to head out tomorrow 40 minutes before sunrise. But if it comes down to it I'll order the cable online.

Are you set up to solder the wires to the replacement plug??

get some heat shrink tube too to reinforce the insulation ..

I just buy extension cables for $4 each and solder them in as replacements.

Also, I would think about soldering in a very short lead out of the light, then putting an extension cable on that. Then when you are unplugging from the battery, you'll be stressing the extension cable instead of the one going into the light. Then next time you kill a connector, just 10 seconds of replacing the $4 extension cable and you're good for another year or two.

Like these, not sure if they're right for magic shine though. They are 5.5mm
5.5mm x 2.1mm Male DC Power Connector w/ Leads - Black (40cm) - Free Shipping - DealExtreme

^^^ if it's not already obvious, the 5.5 is the OD of the shiny part and 2.1 is the diameter of the central pin. There is also some variations in length of the shiny part and though usually not critical, might bear checking.

Edit: Checking some electronic components catalogs I see these also referred to as "barrel power connectors". e.g. https://www.digikey.com/product-searc...r%20connectors

So I went to Radio Shack and got a package of 2 connectors, 5.5 mm x 2.1 mm without the leads. I cut back and stripped the wires coming from the headlight and soldered them to the connector. Before soldering them I just wrapped the wire around terminals inside the connector to test, and got nothing. Maybe they just weren't on well enough? After soldering, same thing. This size connector was the closest thing they had at Radio Shack. After that failure I ordered an extension cable. It should be here in a week or so. I plan on cutting that and splicing the wires to my headlight wires. Hopefully that will work. I wonder why the new connector did not work. Meantime I found an old Cateye headlight in my garage that takes 4 AA's and will use that. Riding mostly in suburban areas so it's more important that I be seen than be lighting up the road in front of me for now. My commute does start with a 2 mile fast downhill down a road with no lights so as it gets darker in the morning I will need that MagicShine back.

1. Are the connectors the right size? Close enough doesn't count, it's gotta complete the circuit.
2. Is there a short with your wiring?
3. Did you get the polarity correct?

1. Well they do slide in and out too easily for my comfort. The original is very snug (which is why I pulled the thing apart to begin with)
2. I don't think so. The light side is still solid.
3. Yes I did triple check that

Sounds like the connector you got might not be the right size.

Since the original connector is now "useless" you can try carefully stripping off the plastic shroud to expose the metal terminals and try re-wiring it. If that works some heat-shrink tubing would cover it back up nicely.