Need Soldering Advice

Num7

Administrator
Messages
9,820
Hey guys,

I know some of you have much more experience than I do in soldering electronics, so I'd like to have an advice.

I'm repairing an alarm clocked that stopped working a few years ago. I changed a few capacitors and it now works. But the wires and contacts connecting the tiny speaker broke apart and I'm not sure how I'm supposed to fix it.

I highlighted the disconnected wires and identified where they're supposed to be attached back to the speaker on the photo below.

1612623259539.png

Here's another shot, showing the underside of the wires.

1612623363599.png

I'm wondering the following:
1. Am I supposed to remove the small bit of printed circuit that remained attached to the wires?
2. How am I supposed to solder these back on the speaker, and where? I don't see any sort of contacts or pins on the speaker.

Thanks in advance! :)
 

Einstein

Temporal Engineer
Messages
3,906
I think you need a new speaker. That small circuit board is part of the speaker. From the picture I don't see exactly where the break off point was. Maybe get a magnifying glass to do a closer inspection to see how it came apart.
 

start at edge

Member
Messages
442
Hey guys,

I know some of you have much more experience than I do in soldering electronics, so I'd like to have an advice.

I'm repairing an alarm clocked that stopped working a few years ago. I changed a few capacitors and it now works. But the wires and contacts connecting the tiny speaker broke apart and I'm not sure how I'm supposed to fix it.

I highlighted the disconnected wires and identified where they're supposed to be attached back to the speaker on the photo below.

View attachment 10751

Here's another shot, showing the underside of the wires.

View attachment 10752

I'm wondering the following:
1. Am I supposed to remove the small bit of printed circuit that remained attached to the wires?
2. How am I supposed to solder these back on the speaker, and where? I don't see any sort of contacts or pins on the speaker.

Thanks in advance! :)
Yes, Einstein is right – you need to find another speaker of the same size (and impedance – the one in the picture must have something like 4 to 16 ohms), so that you can fit it in the same place. The speaker you buy may have those 2 pins much closer to the circular magnet (closer to the center) – it is perfectly OK to solder your wires to those pins (though, try not overheating them).
 

TimeFlipper

Senior Member
Premium
Messages
10,708
Hey guys,

I know some of you have much more experience than I do in soldering electronics, so I'd like to have an advice.

I'm repairing an alarm clocked that stopped working a few years ago. I changed a few capacitors and it now works. But the wires and contacts connecting the tiny speaker broke apart and I'm not sure how I'm supposed to fix it.

I highlighted the disconnected wires and identified where they're supposed to be attached back to the speaker on the photo below.

View attachment 10751

Here's another shot, showing the underside of the wires.

View attachment 10752

I'm wondering the following:
1. Am I supposed to remove the small bit of printed circuit that remained attached to the wires?
2. How am I supposed to solder these back on the speaker, and where? I don't see any sort of contacts or pins on the speaker.

Thanks in advance! :)

It might be useful removing those 2 screws and plate that hold down the loudspeaker and finding out if there are any loudspeaker connections underneath it, the impedence should also be written on the metal back of the loudspeaker coil....The circuit board looks a bit abused, you said you changed some "capacitors" and now it works, so therefore the loudspeaker "must" have been working upto that point...

How did you re-connect the old capacitors, did you cut off the wires from the old capacitors but left sufficient wire from them, so that you could wind the 2 new capacitors wires around them?....How did the loudspeaker wiring from the circuit board get disconnected from the loudspeaker, was it when you was working on the Alarm Clock?...

If you really want to know how to solder which was your first concern, hopefully you will enjoy the starter video, but there are many other things you will need to know such as when to use a heat sink for example....Or if you would rather just want to know how to get 2 wires stuck together without any lead (Pb) or nasty chemicals involved in it, buy some "Wire Glue" or in some adverts it will says "Glue Wire"...Its really cheap, highly conductive and simple to use, it only takes a few hours to "set" :)..

Alternatively, wind the wires together then wrap insulation tape around them, or just Sellotape (not recommended!!) :LOL:..

 
Last edited:

Num7

Administrator
Messages
9,820
Thank you guys, it makes sense that the contacts might have come off with the small bit of printed circuit. I'll remove it and check it out.

I changed the capacitors by unsoldering them and taking them off and putting back new ones. 2 of them had inflated over time. The one you see in the photo was among them.

I used to repair computer monitors a few years ago, LG ones would have their capacitors literally burst after 3 to 5 years. I got pretty good at taking them of and replacing them.

I'll take a look at the speaker and let you know more. :)
 

Einstein

Temporal Engineer
Messages
3,906
I have a picture of a speaker here for clarity of the possible repair you might be able to do.

1HwLtPWhYDPOJd6w.full


In the picture you can see the terminal connector block permanently attached to the speaker. Yours is broken off. It could be reattached with epoxy glue. Underneath the terminal block are some flexible wires. On your picture those flexible wires are not in sight. Remove your speaker and see if those flexible wires are there and just hiding out of view. If they are there take a resistance measurement with a multi-meter. The value should be close to the printed value on the back of the speaker frame. If the value is very high, you'll need to replace the speaker. If OK then it might be possible to reattach those flexible wires by soldering them back on to your mini circuit board (terminal block). Those flexible wires are part of the coil and speaker assembly. If you find them pulled loose or missing then you'll need to replace the speaker.
 

Num7

Administrator
Messages
9,820
Thanks Einstein, that gives a good idea of what to expect. I'll keep you posted.

TF, I don't know how the wires came off the speaker. Maybe I wasn't careful enough when I opened the device and it came off. That's a possibility. All the electronics in there is pretty cheap, to be honest. Very cheap.
 

Num7

Administrator
Messages
9,820
Ok, I took off the speaker and look at it. The wires were completely torn off, there's no way I can connect anything back to it.

I found the exact component on Amazon, it's pretty cheap but I had to order a pack of 4! I guess I'll have spare parts next time it breaks! :geek:

1612651702038.png

With a new one like above, I'll be able to connect back the wires to the speaker's contacts and it should do the trick.
 

Martian

Active Member
Messages
855
Come on, Num, a new alarm clock is like $5. :D Just kidding.

I don't have much to add to what the others said, but after the soldering is done, I sometimes use hot glue to reinforce the wires at the connection so they are unlikely to come loose again.
 

Num7

Administrator
Messages
9,820
LOL I thought about it, but it's no ordinary clock. It's the ThinkGeek Epoch Clock:

1612658378335.png

Among other things, it's able to display time the normal boring way hh:mm, in Roman numbers, binary, hexadecimal and octal. Also, in the bottom left, it shows the Unix time. It's the number of second that passed since Jan. 1st 1970.

I've used it for years until it broke down. I decided to repair it only recently. They don't make these anymore, so I figured I might as well try to repair it, it already didn't work anyway. Worst case scenario, I'd buy a used one on Amazon or Ebay, they show up sometimes.

The glue is certainly a good idea I didn't think about. It would reinforce things quite a bit. I'll probably glue the little speaker's connection when I'm done.
 


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