Faulty mixer inputs

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Hi, hopefully this is the right part of the forum for this...?

I have a vestax PMC-05 DJ mixer which is in good condition except for the fact that every now and then the left input of one channel drops out or goes quiet. Then if I turn the unit on/off once or twice, causing a large clicking noise, this fixes it.

Wondering if this is indicative of an obvious problem?

I opened it up and had a look at the solder points... they look fine although that one is perhaps a bit yellowed... and I can't really get in to take a close look without serious disassembly.

If it was a weak solder then turning it on and off probably wouldn't fix it right?

Also, I've narrowed it down to that input because the other channel works fine so its not the outputs. Also have tried other leads.

Any ideas?


Thanks.
 
more indicative of a failing soldered joint is you can make the channel come and go by giving the mixer a good knock , tapping the circuit board with an firm piece of plastic around the channel whilst powered up and handling signal would get you closer ( if you can make it come and go this way ) .
 
Hey guys thanks for your suggestions. I resoldered the inputs and it seemed to have worked for a bit... but then the faulty input (CH1, left side) dropped out again...

I'm going to try again as I may not have done it right, but one thing I just noticed is that the faulty left side lights up the meter for that channel even when its not making any sound (and nothing else is plugged in, including the right side of that channel).

(It seems that on this particular model of DJ mixer, the meter for each channel only reads the left side on of the stereo input - on both channels the meter will light up with a signal from the left channel but not the right. Both right channels are producing sound fine though.)

So, even when the faulty (CH1, left side) input is not producing sound, and nothing else is plugged in, the meter for that channel is lighting up fine.... Which would seem to mean that the problem is not with the input itself but something further along the signal chain, beyond the meter... Am I right???

Thanks again!
 
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