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View Full Version : L220's intermitent, ideas?



Ferret
04-20-2008, 11:16 PM
This problem has been going on (and off) for a few years now. When listening at lower volumes, one of the 220's will cut out. Turn up the volume, it's back on. Problem is, the volume needed to keep them on all the time is a little too loud for normal listening. One had the problem but a cleaning of the input posts cured it. I've replaced the speaker cables and used different amps and pre-amps and it still happens. Any ideas? Or, know of any good JBL repair shops in New Jersey? Thanks!

Allanvh5150
04-21-2008, 12:12 AM
hi Ferrett,

If the whole cabinet is going on and off, I would suspect a bad cable or internal cabling inside the 220 from the input posts to the crossover. Have you tried swapping the speakers to the opposite channel on you amplifier to make sure that the amp isnt at fault?

Allan.

Ferret
04-21-2008, 11:09 AM
Yea, first I though it was a bad pre-amp channel, swapped that out, same thing. Then I tried different amps to no avail. It's definitely the speaker. I'm hoping its not a bad cap within the crossover, but I'm thinking if it was, it would only affect one driver. I'll crack her open and have another look. Thanks!

grumpy
04-21-2008, 12:58 PM
Manual:
http://manuals.harman.com/JBL/HOM/Owner%27s%20Manual/L220%20om.pdf

Tech info:
http://audioheritage.org/vbulletin/showthread.php?t=5630

Schematic:
http://audioheritage.org/vbulletin/showpost.php?p=36939&postcount=5

oznob
04-21-2008, 01:57 PM
I would check the adjustment pots, L-pads, first. They are in the signal path and can affect the sound if corroded or dirty. You could try turning them back and fourth vigorously and see if that makes any difference. If that doesn't work, you could pull them and hose them down with some "Deoxit" or any other electronic spray cleaner/lubricant.

Good luck!

grumpy
04-21-2008, 03:05 PM
If the sound intermittently goes -completely- off (no sound from bass, mid, or cat-eye
tweeter), then I'd be looking at the internal wires/connections that go to the -inside-
of the input terminal panel... (top left in schematic) -grumpy