Nitecore UM2 -- Micro USB socket separated from PCB

Thanks — that’s the charger. I see that it’s from a video that’s not in English. I looked at it with a loupe and yeah, those 5 surface mount contacts are there. I do not have the solder precision skill to work with something that small… so, at least I’ve saved myself the time of trying to do it!

The port appears to have broken clean off. I don’t see any solder traces on it. But from the video (HERE), apparently it was a clean break. The solder pads are so very tiny… no way I could do that given my primitive soldering tools.

Anyway, the port still works, the board works… it’s just the contact problem. I’ll reach out to Nitecore about it, see what they say. Thanks for the tip!

Good luck and let us know what Nitecore says.

Yeah, they’re small but those are still relatively easy as long as you can see what you’re doing. :slight_smile: Hopefully Nitecore takes care of you and gets you back in business.

I had to look up that site…he’s still selling all the bits. Gosh, he carries 100 of them! lol. Just for fun, here’s a photo listing of what he stocks. And these are only micro-usb styles! Scrolling down it all becomes a blur and they all look the same, but they’re all different and probably none of them are interchangeable on the same board. Sheesh.

Well, I heard back.

Yeah, wear & tear is expected, but this is poor construction. I’ve many, many Micro USB devices that are many years old and the port hasn’t broken on them.

Mailing to China is probably going to cost me $12. Return cost will probably be cheaper, like $4.

I bought the charger from Battery Junction for $19. At this point… doesn’t look like sending it back is worth it.

Yeah, that's not normal wear and tear.

That poor construction (like you said.)

Nitecore should be ashamed of themselves.

Maybe the PCB pads are ripped and you just don’t see them.
The only way to properly fix it is to find a replacement USB socket (on AliExpress) and to resoder it.
This being a micro usb it’s fairly easy to fix. You can do it with a cheap soldering iron, soldering wick, flux and soder.
Maybe you could use epoxy to hold it in place but it’s doubtful if you would get a contact and you’re basically ruining the PCB.

One quick and easy method is to use an automotive heat gun instead of a hot air station that I assume you don’t have. It all depends how skilled you are and how willing you are to learn.

If you were closer I could fix it for you. Decide if you want to give it a go. The tools shouldn’t be too much. Probably cheaper than paying someone to do it and you would have them afterwards so you could fix other stuff. It’s a valuable skill to have.

The 5 pad group on the PCB looks to be intact. I don’t understand why I’d need to buy a replacement USB socket, as the current one is OK—just detached. Ideally, I’d love to swap in USB-C, but I doubt the solder points are compatible.
I have like 3 different soldering irons, but none of them have very fine tips. I’ll have to recheck to see if any are detachable. I do have flux & solder, so I could attempt this. Does the PCB surface have a special non-stick coating to help keep solder from spreading? I’m just concerned about accidental bridging across several pads.
Frankly, if I’m not going to send it back for repair, it may be worth my time to experiment and see about doing my own repair, and like you said learn from the experience. I’ve soldered before, but only single pad+wire scenarios.

That’s pretty easy to solder. First push the socket onto the board and solder the two pins that go through the PCB (if you can push them through, then this thing was never soldered in). Next solder the five little pins. Just swipe away from the connector with little solder and some flux. Inspect for bridges, but if you don’t use too much solder and enough flux it should be nice and clean.

pretty sure J1 in the photo is one of the two symmetric through hole solder pads to affix the usb port to the board. maybe check those. if the data pads arent damaged, choose a large iron tip, tin it wih solder, and “scrub” it across all the pins at the same time. When you “wipe away” the mix of old and new solder with the hot iron, carefully tin your iron tip with a little new solder and “scrub” the pins again and will magically look new.

I wrote you a long and extensive reply yesterday but it fell through because of the maintenance being don on the forum.

Usually you never resoder the old part because it doesn’t cost more than $1 and you can’t be sure it’s 100% working. If you’re already putting in the effort you don’t want it to fail a week after because you decided to save a few cents.

You could do the USB C conversation if you find a socket that fits the fixing/mounting holes on the PCB but it would be quite a hassle to do even with good equipment and experience.

You don’t need a needle tip but you want to be able to touch each prong/contact individually. You can put the soldering iron tip in a drill and push it against sand paper while spinning to make it more acute.

You should remove the old solder with the wick, clean the PCB with alcohol and check for damage under magnification to see if none of the pads is missing. Maybe all of them are gone but the outline makes it look like they’re there. I would definitely recommend using some sort of magnification when doing this.
You should clean the mounting holes for the legs with the wick or otherwise you won’t be able to reinsert the connector (assuming it’s not broken)

If everything is ok rapply new solder on the pads. Use a lot of flux before you desolder and when you solder the part back on.

The flux does the majority of work for you so don’t forget to use it.You should have enough solder on the tip so the process goes smoothly but not a blob so it bridges contacts. If it does,you can run the tip along each contact so the soldering tip picks up the excess. Don’t run the tip across because it will bridge the contacts. If you can’t get it off the last resort is the copper braid which will take it off. Ideally you would want to test each contact with a toothpick to see if they move or if they’re soldered properly. You can’t go by your eye.
You should first connect the pins and then the legs that go into the PCB.

It would help to see a picture of what’s going on.

Usually something breaks if the port comes loose because those legs hold the connector in place.

Please never do this with a modern plated tip!

I assume he doesn’t have a $200 soldering station but generally speaking you’re right.

On a cheaper soldering iron that gets used once a month it won’t matter.

Indeed! Good way to destroy a tip instantly - if it doesn’t bother you financially if you’re using the cheap-o china tips, then it will surely frustrate you when you discover it transfers far less heat, doesn’t wet/tin, and oxidizes to the point of death in one or two sessions. The layers over the core are thinner than one might expect and as soon as one or two is compromised you may as well replace the tip asap.

They do sell solid copper tips - not sure what their application is exactly but they are short lived and disposable. Those can be formed as you wish, though.

This simply isn’t true. For decades people used regular uncoated tips and they got the job done.

This is the tip of my cheap soldering iron station that I modified three years ago if not more and I use it for fine work.

The bottom half is still nickel plated. Only the tip was sanded down. It works as before, it takes solder and it’s obviously not burned out.

More powerful soldering irons will burn out much quicker but you don’t use a 60W on smaller electronics.
It takes ten, twenty seconds to warm up and you turn it off when you’re done. We’re not talking about professional equipment.

Thanks for taking the time to reply with that level of detail. Sorry you lost your original! One little tip — whenever I’m typing a long message in the website forum editor, before hitting SAVE, I do a select all and copy into the paste buffer. Just in case there’s a server error. If there is, you can try again… and if it’s down for a while, just paste the text in an editor and save for later.

Lots of great advice here. Yeah, my soldering experience is very limited. I’ve done just single wire to pad type stuff. What you describe I’ve seen take place in some soldering videos… I just didn’t fully understand what was happening. You’re absolutely right—I do not have a soldering station. I’ve got like 3 soldering irons, each of a different wattage. It was the result of “can’t find that soldering iron” and buying another, only to find the older one some time later. Once my life settles down and I get serious about making LED modding a little hobby, I’ll invest in a good soldering station. So, meanwhile, I think I’ve got enough to do the job. The curious solder behavior on the pcb when dealing with multiple pads close by is tricky to understand for the novice, but I think I get it now.

And thanks for the tip about the USB socket. I think you’re right—better to get a replacement. I just don’t want to end up paying much. If I can get another UM2 or equivalent charger for about $20~25 and the USB socket with shipping comes to about half that… well, not worth it! I’m going to reassess… see if there’s another 2 slot charger around that’s of equal or better quality to the UM2 and priced about the same. And then, fixing the old one, I’d use the original port and hope for the best. Either it works and I’ve got a backup charger, or it fails and I learn!

I will politely but emphatically say that it is very true. As with most things, it does depend on a few factors. In your case those points have a little more iron meat at the very tip which helps to extend life a bit.

Tips (good tips) are a core of copper covered in iron and plated with nickel and chrome. Some of the cheap china tips that you see in packs of six or ten are junk with brass cores and/or very poor plating. The copper is the mule for the heat of course, and iron is highly resistant to tin reaction. The exposed part of the tip is the iron. The nickel plating is I think just there because it won’t wet with solder and allow it to spread up past the tip. Chrome is just for durability.

Once you breach the chrome it doesn’t take long for the nickel to get compromised, exposing the iron. When that happens, a whole bunch can happen depending on what type of flux you use, how much heat, and any abuse like applying pressure. The flux and oxygen exposure will eat at the iron until it pits or sometimes cracks. RMA fluxes and some no-clean fluxes are generally ok but the more active the flux is the more it will “clean” the iron, wearing it away pretty quickly. Once the iron pitting is bad enough (which seriously can happen in one session sometimes) then the tin can reach the copper where….you’re done. Tin will eat up the copper in no time and the flux is still there to affect everything, too.

So when you abrade/shape a tip and nick/scratch/remove the plating materials it just hastens death. This is why drag soldering and doing fine-pitch smt chips wears out tips so fast. I’ve done this a couple times myself but that was before I learned how to solder well, and trying to rescue basically dead tips (I had the bad habit of letting the iron sit hot for awhile at higher than necessary temps and not refreshing the tinning often enough nor storing it with a good blob). What you can do when you want/need to do this is try to tin the damaged area…exposed iron will take the solder tinning until it gets oxidized enough. And then you can try the stinky ammonia tip tinning paste, but those are a last resort and end up hastening tip death especially if the iron is in poor shape. Actually about a year ago I tried this to rescue an abused cheapie Radio Shack iron tip at work…kinda got it better but it petered out two short jobs later.

Something else is the type of iron. Like yours, I’m assuming, is the basic cheap iron, no “smart” temp controls and such. Damaged tips on those may wear a little slower than the irons that have quick response heat control (temp rather than a straight wattage feed).

Sometimes it’s worth it if you need a special shape and can’t get the right tip, or worth trying to rescue an abused/dying tip, but for $1.50 tips like yours or maybe even $8 tips like the regular Hakko….may as well just buy the right tip/new tip. With the expensive long shaft tips and some others, really pays to take care of them.

But if you really go to modify a tip heavily and expose any copper…done.

xevious, I think it’d be fun (sort of) and good practice to give it a shot! Maybe give the port a good look under magnification…if it looks ok and the pads on the board are fine, solder it up. If you search youtube for “soldering usb port” and maybe “drag soldering smt chips” there are lots that show the technique. Dragging or wiping…similar but different, but any of those videos will give you the idea. Not too hard, just remember that flux is your friend, and paste is much better here than liquid. If your tip will fit in that area, try it out, plug it in for a test and keep an eye on things the first couple times until you know it works and trust it like the original. If the port or board is damaged, probably would make more sense to buy a charger since they’re cheapish unless you can get creative like that video above where he jumpered the traces.

I usually make a backup if I write more than two sentences but this time I didn’t and bad luck struck lol.

You can get USB sockets cheap on AliExpress. The wick is also cheap and it will last you a long time if you don’t solder much.

For tutorial videos try this. I skipped through but it should be fine.

^ Thanks for the tips!
I do have a backup charger… a 4 bay Nitecore i4. It’s not very good and there’s no display. But it’ll do for now until I figure things out.

I imagine you got this dealt with one way or another by now but. But I had the exact samething happen to my UM2 and i just said heck with it and cut the micro-usb end off the cord and just directly soldered the other end of the cord to the board. If you have a multimeter you can trace out were each pad goes and solder the wires there its what worked for me. I did this about 2 years ago. But now im dealing with components Q7 and Q8 that burnt up so slot 2 no longer operates, im debating on replacing them or just the entire charger at this point.

1 Thank