I have an EP175 subwoofer, about 12 years old. I found recently it was not working and saw that the LED stays red when the sub is turned on. What are the possible causes? It is driven by a Denon AVR S730. Any suggestions appreciated.

One thing that wouldn't hurt to try is unplugging it and leaving it that way overnight, just in case something internally got into a wierd state. Probably won't help but you never know - it fixes my washing machine every time it gets into a snit

Good idea, but no go. However I found the input coax port is a little loose. I'm going to remove the back panel & check it out. Hopefully I won't make it worse.

Still looking for possible causes. Sub does not leave standby mode, I presume. I removed the rear panel and just looked for anything out of place or burnt and nothing to see. Can someone point me to a manual on subs? I thought Axiom had user manuals online but can't find them at their website.

I found the owners brochure; no clue regarding troubleshooting. Posted to the AVS forum which has some additional info and corrections. This is an EP350 v2. not the EP175.

revised post:

about 1 -2 minutes after turning on sub, it switches from on (green light) to standby (red light). If I remove the input RCA cable, it switches back to "on" for 1 -2 minutes and will output a test tone and then switch back to standby. I noticed that the RCA input port is _slightly_ "wobbly" - not really loose but it will rock back and forth slightly if pushed. In comparison, the output port is solid. I removed the back panel and looked at the port from inside and could not see anything out of the ordinary, eg loose wires, burned component...

Does anyone have any ideas?

This is an Axiom EP350 v2 sub purchased about 12 years ago.

Thanks for any tips.

More info - when the sub is on, the receiver recognizes it when I run a speaker tone check. When it is in standby, the receiver does not see the sub. Regarding the on/off switch, it's either off on auto. There is no "on" position.

It appears a loose input port is causing the problem.

Using the second connector. They are not really "input" or "output", but interchangeable for daisy chaining.

Agreed - I have a V3 EP350 and a V2 EP350, just use the second/other input jack.

I tried it and got the same result. Wondering if practical to do an amplifier repair.

problem resolved. cable connector at sub is faulty. replaced cable and sub works fine.

That's great news!

I had a similar problem with an RCA cable from the pre-amp. Brand new cable was faulty, I thought initially one of the channels of my amp was done before I tried another cable...phew!! didn't relish the idea of shipping a 75 lb amp back to the manufacturer!