Popping sub woofer

[Leeerox]

Hi ,, after my first successful post i thght il have a go at a 2nd inquiry!
Ok, so i have an onkyo tx 607 av amp powering a powered sub-woofer, has been fine for 3yrs but has started randomly 'popping'.after initial search this turned up faulty capacitors could be the cause, which iv examined for any sign of distortion or leakage but all 'seem' ok any ideas on how to rule out capacitors or any other ideas?? Thanks in advance

 

[Leeerox]

The sub is a Tannoy SFX 5.1 !

 

[Arouse1973]

Popping subs could indicated a D.C level being applied to them. This could indicate a capacitor as they are supposed to block D.C. You could either replace the capacitor or measure the output with a multi-meter to see if there is and D.C voltage on the output.
Adam

 

[Gryd3]

Popping subs could indicated a D.C level being applied to them. This could indicate a capacitor as they are supposed to block D.C. You could either replace the capacitor or measure the output with a multi-meter to see if there is and D.C voltage on the output.
Adam

Carry out the steps above, but please also give more detail about when the device 'pops'.
Does this only occur on power-up or power-down? Does this happen randomly when listening to music/audio?

 

[Leeerox]

Yes, its completley random,, dont see no pattern,, ie hasnt done it once all evening whilst its been on. there a numerous capacitors inside, but il get the multimeter out!

 

[Arouse1973]

Yes, its completley random,, dont see no pattern,, ie hasnt done it once all evening whilst its been on. there a numerous capacitors inside, but il get the multimeter out!

Measure across the speaker terminal in standby, no audio.
Adam

 

[Leeerox]

Ok, so heres the inards!

 

[Arouse1973]

On the green PCB top right of it is a funny marking I can't make out, looks like a track with a strange shape. But it might be the lighting.
Adam

 

[Leeerox]

Well spotted,, its a grounding wire, i think ,, goes to a 'buzz bar' and transformer mounting plate. Looks like its soldered straight onto the track???! with a blob of glue,, seems secure tho