Please help a newbie repair a "hand clapper"

Sep 15, 2007 14 Replies

I think, that's some glue (sometimes waxe) to fix parts and not caused by leaked capacitors. It's not a perfect but cheap/common method to prevent failures from vibrating parts or changing values/adjustments in some high-frequency application.

I don't think, that that's your problem. Look for could solder points, bad (corroded) contacts, broken copper, cracks on the pcb...

Saludos Wolfgang

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Hi!



I have a BOSS HC-2 hand clapper that is broken



The problem is that it makes crackling noise when I touch the pcb. Since the audio connecters are wired to the pcb it crackles whenever the cord is touched.



I have almost zero experience in repairing stuff but I want to learn, and since it's not a very expensive item, I think it makes sense to practice on it. Taking it appart it looked to me as at least of the capacitors had leaked? Could that generate crackling noise?



I took this picture:



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What do I do?


Looks like glue to me. Flip the board over and in good lighting start wiggling some of the stand up mounted components and see if you can find some soldered joints where the lead moves on the soldered side of the board.

The solder joints on the wires look suspect. You might want to remove the solder and re-solder them.

thanks for the replies. Unfortunately I couldn't find any other problems. All the solder joints seems fine, and I couldn't find any cracks in the pcb. I'm suspecting that the output jack connector socket is the problem, so tomorrow I will try to solder the cord directly to the pcb, to see if I'm right.

If you carefully touch each component with an insulated stick, something like a chopstick, and each wire, you should be able to find out the area of the circuit board that is most sensitive. The material in the photo looks like cheap hot glue which the manufacturer used to hold down wires that might flop loose during the final assembly.

H. R. (Bob) Hofmann

I did that, and maybe it seemed like the most sensitive part was a Roland IC named BA662310A. But I could be wrong, since it was very easy to bring out the crackle everywhere on the pcb. I should hardly touch it with the chopstick. It wouldn't be the first time roland made bad chips though.

Anyways, I probably have to buy another hand clapper. Thanks for the all the good advises. I will remember those next time something breaks.

As you will probably be buying a new unit, it can't hurt to experiment with the one you have.

Just because solder joints "look good", that doesn't mean they are. And the solder joints on that board don't look very good. I would unsolder and resolder all the wires connected to the board.

can you show us a pic of the other side of the board in that area?

Ron(UK)

Gret your soldering iron out and resolder every connection :)

That was almost impossible because the board was reflecting light and so my cam couldn't focus. Maybe I can take a better one in daylight tomorrow.

Here's the best one

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Enable Macro focus for close-ups.

Well firstly try resoldering the pins on that chip. use a good magnifier to inspect every joint on the board and resolder any that seem even slightly suspect.

Ron(UK)

The solder joints on the pins looked perfect to me. But they weren't. I reheated the solder and now it works as it should I think.

Thanks for the help. It felt really good when I plugged it in and realized that i worked again.

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