My JBL PSW-D110 started humming loud... The fuse is fine and the power LED displays is illuminated in green. However the sound is unbearable... It would like to replace the entire IC panel if its most cost effective. I contacted JBL online and they have no authorized service center in my area.  Based on the description below does anyone have any idea where to start as I don't have the schematic? Any help would be appreciated. Thanks. MARK

I would say it's a case of bad filter capacitors in the power supply. Without the capacitors, the AC power line doesn't get smoothed out enough when converted to DC by the supply, and you hear the hum that gets through. I have never worked on on one of these so I can't tell you how to open the case to get at the supply. It's not always a simple job. But if you can get at those caps and check them, you'll probably find them at fault. It's not a difficult job to remove and replace bad capacitors if you are comfortable using a soldering iron. Just make sure that replacement parts have at least the same voltage voltage rating and capacitance values as the originals. It never hurts to go higher by a little, but not lower.

You can use a cap of same or bigger voltage,

Hi,
Hummmm is from Output amplifier and you need to replace it because power supply blow it too.

The Class D module may have failed,
Service manuals:
Psw-d110_DPS-10_RevF sm.pdf

Please leave rating if it helps.

JBL uses badly design amp modules.
http://s807.photobucket.com/albums/yy352/budm/JBL%20PB-12%20mod/

Basic LCD monitor and TV troubleshooting guide:
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide
http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting
http://www.fixya.com/support/r7406380-tv_training_manuals
Failed TV and Monitors: http://s807.photobucket.com/albums/yy352/budm
Learn about bad caps: http://en.wikipedia.org/wiki/Capacitor_plague
Parts: www.shopjimmy.com
Capacitors kit: http://lcdalternatives.auctivacommerce.com/Default.aspx he can make you a set of caps.
Or www.digikey.com, just make sure to use caps with low ESR, 105c, high ripple current and long life rating such as PANASONIC FM or FC series.

get connected to the following
www.glolab.com/freeinfo/info.html-11k
or
www.vitage-radio.info/heathkit/-78k

here is the manual, I am looking for a more detailed version

Look at this post:

http://www.fixya.com/support/t3533583-subwoofer_will_not_product_sound_ignore

There is a standby indication that activates after 10-15 minutes without any input signal. I suspect that might be what the red light is telling you - no signal.

Loud hum from a loosened cable is normal as hum usually means there's an ungrounded connection somewhere acting as an antenna and the amp is doing its job to amplify what it thinks is a signal, in this case 60hz stray ac current is being sensed nearby. It's a good sign that you get hum from the sub because that means the amp is alive.

Avoid manipulating cable connections with the Sub or Receiver turned on as you could introduce a static spike that could harm any connected equipment.

Are you certain a bass signal is making it into the sub? The complexities of modern AV receivers vary in how you configure them to direct LFE to a sub. Bone up on that end of the chain.

Or, just hang a CD player on the Inputs of the sub and play something with a reassonable amount of Low Frequencies.

>>>> Be advised that this way of testing has NO VOLUME CONTROL because amps without volume controls always operate at maximum gain, relying on your external controls to attentuate it (hence, the loud hum from a loose cable); so choose a track that eases into the loud parts with some quiet parts up front and BE READY TO PAUSE THE PROGRAM AT ANY SIGNS OF STRESS. <<<<

A living sub will produce only muffled rumble in the absence of other speakers producing the higher frequencies which carry the intelligence of the signal. If that works, back to the receiver for settings. If not... sigh.

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For hum problems, even those you cause yourself:

Disconnect all inputs to see if that helps. If it goes away start with the signal cables and add in things until it comes back.

Sometimes the reversing the orientation of the AC plug can help with hum. Or it could be something like a loose or high resistance connection internal to the sub. Good luck.

Hi Chadwik

The fact that you do get hum when you partially remove one of the RCA's would tend to say that the output stages are working ok. Is the hum "solid" and bassy, or distorted?

There are a few issues that these subs have had, mostly to do with capacitors in the power supply failing. If you are up to it, I can talk you through repairs to it.

regards
robotek

If I remember these correctly, there is a bad coupling cap in the amp section. You should see it as the top should have ballooned up. Replace the cap and you should be OK.
Dan