Had an interesting failure of two JBL VP7212MDP wedges last night. The boxes don't belong to me and I've got no dog in this hunt other than helping out a friend, but maybe someone with more VP series (or DPC amp) experience may have a better suggestion.
Mid-show, one wedge dies. Power & signal lights are still lit as normal on the amp module, but nothing is coming out of the drivers. I walk out to the truck to get a spare, and in the 2 minutes it takes me to get out there and back, the wedge has come back to life. However, not wanting to risk a failure again, I swapped it out with another wedge.
A few minutes later the second wedge dies in the exact same manner - power light is still on, signal light still flashing. Neither wedge was overheated - both amp modules were still cool to the touch.
As far as power, the wedges were in the middle of 3 boxes looped together via Powercon. Boxes on either side are fine, so I don't think it's a power issue. Here's the interesting part: in unplugging power while signal is still plugged in, right before the caps in the amp fully discharge and the wedge turns off, audio comes out of the box for a split second. This was completely repeatable on both boxes, but I've never seen this behavior before.
To recap:
- Wedge "dies" - no audio from drivers
- Power lights still lit
- Signal light still flashes
- Gain pot still attenuates based on LED intensity
- Amp not overheated
- Looped power - boxes on either side are ok
- Unplugging power results in audio for a split second before the wedge turns off, as the caps discharge
Thoughts/suggestions?
Mid-show, one wedge dies. Power & signal lights are still lit as normal on the amp module, but nothing is coming out of the drivers. I walk out to the truck to get a spare, and in the 2 minutes it takes me to get out there and back, the wedge has come back to life. However, not wanting to risk a failure again, I swapped it out with another wedge.
A few minutes later the second wedge dies in the exact same manner - power light is still on, signal light still flashing. Neither wedge was overheated - both amp modules were still cool to the touch.
As far as power, the wedges were in the middle of 3 boxes looped together via Powercon. Boxes on either side are fine, so I don't think it's a power issue. Here's the interesting part: in unplugging power while signal is still plugged in, right before the caps in the amp fully discharge and the wedge turns off, audio comes out of the box for a split second. This was completely repeatable on both boxes, but I've never seen this behavior before.
To recap:
- Wedge "dies" - no audio from drivers
- Power lights still lit
- Signal light still flashes
- Gain pot still attenuates based on LED intensity
- Amp not overheated
- Looped power - boxes on either side are ok
- Unplugging power results in audio for a split second before the wedge turns off, as the caps discharge
Thoughts/suggestions?