True Subwoofer Signature (Sunfire) No Sound

[pirates712]

Originally Posted by Rajesh

Do you hava a red light on when you switch on ? If not then check this.

There are 2 fuse on the power board. if either onne is blown then it could be the output transistors short Q14-Q17 . 2PNP/2NPN . Replace all four even if one is short cause they are connected in parallel.

Check the FET's Q22-Q24 in the possitive rail and Q19-Q21 in the negative rail. Even if one is short replace all 6 FET's . Check for 13v supply on the power board. Check for a short diode near the capacitor area.

Check the comapator IC BA-10393 2 nos if Pin no 8 and 6 measures less than 100 ohms either side. if so replace the IC ,the 13 supply will become stable.

Good luck ! let me know if you need any more detailed help.

Regards
Rajesh
rajesh122@gmail.com

Hey- thanks for the detailed advice! When I plug it in, the red light is in fact on, however, both internal fuses are blown (very much so, as in molten metal stuck to the glass). Do the above suggestions still apply?

[Rajesh]

Originally Posted by pirates712

Hey- thanks for the detailed advice! When I plug it in, the red light is in fact on, however, both internal fuses are blown (very much so, as in molten metal stuck to the glass). Do the above suggestions still apply?

Hi,

Then it's a lot easier. Your 13V is stable . Your op-amp is fine . All you need to do is check Q14-Q17 . The fuse will blow only if this transistor shorts. Remember to change the driver transistor as well. Q13 & Q18 . The unit should be restored.

As a caution check these diodes D10-D13 . D-10 has a resistor in parallel so it will read 39 ohms. The other diodes are 1N4148,replace all 4 even if one is short. Good luck to you .


Regards
Rajesh

[pirates712]

Originally Posted by Rajesh

Hi,

Then it's a lot easier. Your 13V is stable . Your op-amp is fine . All you need to do is check Q14-Q17 . The fuse will blow only if this transistor shorts. Remember to change the driver transistor as well. Q13 & Q18 . The unit should be restored.

As a caution check these diodes D10-D13 . D-10 has a resistor in parallel so it will read 39 ohms. The other diodes are 1N4148,replace all 4 even if one is short. Good luck to you .


Regards
Rajesh

Ok, can I check Q14-Q17 while they are on the board, or do I need to remove them?

[Rajesh]

You have to remove them to check .Else remove the emitter and collector of the transistor atleast . Remember they are connected in parallel.

[dw886]

Hey Pirates712 -

Did you ever get your sub working? I have a True Subwoofer Signature, and the woofer has gone out. So if you're looking to get rid of one of your woofers, I'd be interested. I'm looking for a 12". The part number on mine is: 585-002-12

The amp on my unit functions fine, I'm just missing the woofer :-(

Let me know.

Thanks,
Derek

[pirates712]

Ok Rajesh, I replaced the parts you specified (except for the diodes). I still get the red light and nothing else. I did notice that it does get brighter for a second after I unplug it just before it fades out. It it imperitive to replace the diodes? Any other ideas at to what could be wrong or should I call it quits?

I'm going to keep them for now. If it seems utterly useless I may consider selling a woofer.