Repair subwoofer Yamaha YST-SW320

[krneki10]

I have several years old subwoofer Yamaha YST-SW320 which started to slowly die this week. At first, it was playing sound just like it should with some noise here and there. This noise has became more and more often and there were also several silent breaks. As of moment we are speaking, it will play sound only for a few seconds per minute.

Is there any way that I could fix it? Perhaps replacing capacitors could work? Please notice that I have limited knowledge in electronics.

Thanks for help.

 

[cowboybob]

Here's a service manual:
View attachment 67098

Page seven has the schematic for this unit.

Troubleshooting is straightforward (as with most audio systems) but by no means simple, depending on your level of comfort with this sort of task.

 

[ben7]

Definitely sounds like a bad solder joint.

Open it up, and take a look at the solder joints on the back of the PCB. They should be smooth, and not cracked.

Take a look at **broken link removed**.
Pic 1 shows a good solder joint.
Pic 2 shows a bad solder joint, with a circular crack in it!

 

[unclejed613]

also. check and make sure the spade lugs on the woofer are tight. these often become loose in subwoofers. removing and retensioning the grippers will usually fix this. occasionally the tinsel wires in the woofer wear out, and would cause dropouts as well as noise. the tinsel wires would look darker near the break, because the remaining wire strands heat up during operation.

because the amp is within the woofer cabinet, the most common problem would be, as already mentioned, bad solder joints.