JBL Powerbass PB12 When left on, will make very loud sound

Before you spend a lot of money, try checking for these:

- poorly soldered or partially desoldered wires, connectors (power, signal input) or ANY other components (especially the ones that tend to heat up, like power transistors or voltage regulators - a component which has been heating up will cause the curcuit board around it to become somewhat darker)

- dirty or oxydized contacts on ANY of the connectors or switches

- partially or fully blown electrolytic capacitors (see if any are damaged, bulged or blown at the top, these surely need to be replaced)

- internally damaged tantalum electrolytic capacitors (probably there will be no apparent damage to these, but they may cause intermittent disturbances if they are bad).

It may as well be something else, but if your equipment was being used extensively during these 6-8 years, it is likely that some capacitors may have dried up or otherwise failed.

It is also likely that the sound vibrations caused loose connections or bad solder contacts on the circuit board since it is a powered sub with an integrated amp (many audio devices get to suffer from bad solder contacts just by heating up with years of use and even without being exposed to powerful sound vibrations).

I hope you can get it to work well again.

regards

3rq8 (Triarcuate)

If you have a pb10 or pb12 and it is not blowing the fuse - then it can be repaired - if it is blowing the fuse and has the ami module then sadly it is a paper weight - please contact us Edwards Electronics - Ebay - We repair amps - sell parts for them etc. and provide technical help. Thanks.