JBL Bass20

[ShawnJones]

First, I have lurked around for a while now and have found some wonderful information here, thanks for that. I look forward to being an active member and contributing some projects as time and money allow.

Here is my question, I have a JBL Bass20 sub for my HT that has recently blown. It was very strange, no problems out of it, one day I went to turn it on and there was a very loud "POP" followed by the distinctive smell of burning electronics. I removed the plate amp from the cabinet and found what looks like a transistor destroyed. The only reason I say transistor is because there are three traces on the PCB leading to the component(SMD). The part is screened as "z1" on the PCB. Does anyone have experience with this amp? I have tried contacting Harmon Kardon and looking for a schematic via google but to no avail.

I would like to just find out what killed the component and repair it, but I have been thinking about just using the parts to try to piece together a new prototype amp for my HT sub. If anyone has a copy of the schematic or can advise from experience it would be much appreciated.

Thanks,
Shawn

[ShawnJones]

Earlier this evening I received an email reply from Harmon Kardon with an attached pdf of the service manual. Thanks to everyone who viewed this thread. I appears that the component the cooked was a zener diode(z1), upon closer examination of the PCB there only appears to be 2 traces to that pad, not 3 as first thought. I'll see what I can make of it, I have attached the schematic for anyone interested.

Thanks,

Shawn