How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Louie Your Own Question
Louie
Louie, Technician
Category: Home Theater-Stereo
Satisfied Customers: 11447
Experience:  Have been in the business 25+ yrs., down to component level.
13948492
Type Your Home Theater-Stereo Question Here...
Louie is online now
A new question is answered every 9 seconds

My infinity 1200 s subwoofer isn't receiving a signal from

Customer Question

My infinity 1200 s subwoofer isn't receiving a signal from my AVR and I have checked the settings on the AVR and subwoofer is turned on but still nothing. I'm about to pull my hair out.
JA: What's the make and model of your tv, and has turning it on been a problem in the past?
Customer: It's not a TV it's a projector
JA: What troubleshooting have you tried?
Customer: Checked the coaxial cable connections and the sub woofer settings on my AVR.
JA: The theater expert can solve this for you. Anything else you want him to know before I connect you two?
Customer: No
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Home Theater Technician about your situation and then connect you two.
Submitted: 5 months ago.
Category: Home Theater-Stereo
Expert:  Louie replied 5 months ago.

Hi and welcome to JustAnswer,

Thank you for the question and your patience. Should you still need assistance for information purposes only...

Initially, bear with us; re-confirm and post back with the complete model number of the AVR.

Customer: replied 5 months ago.
Sony STR-DE875
Expert:  Louie replied 5 months ago.

Appreciate the additional information.

How is the Infinity Alpha 1200S connected to the Sony STR-DE875 using what kind of connection(s); LINE LEVEL (RCA) or HIGH LEVEL (speaker wires)?

And is this a fresh/new install? ...or the pair has been working as expected before and this issue just recent?

Customer: replied 5 months ago.
Coaxial cable hooked up to the Right side of the line level inputs on the back of the sub.
Expert:  Louie replied 5 months ago.

Can you please disconnect the RCA plug to the Sony's SUB WOOFER jack? Lightly touch the tip/center pin of this RCA plug. With the Infinity Alpha 1200S turned on, LEVEL up, there should be a thump/humming sound from the subwoofer.

Please post back results / observations of the above once tried.

Customer: replied 5 months ago.
Let me make sure I understand you. Unplug the coaxial from the AVR and touch the center of that end of the plug with what?? My Fingers??
Customer: replied 5 months ago.
Did you get my question??
Expert:  Louie replied 5 months ago.

Yes, lightly/momentarily touch the tip of the RCA plug of the coaxial cable connected to the Sony's SUB WOOFER jack.

Customer: replied 5 months ago.
Touch it with what?
Expert:  Louie replied 5 months ago.

Touch the RCA tip with your finger.

Customer: replied 5 months ago.
Ok. I touched it and no sound period or noise.
Expert:  Louie replied 5 months ago.

If the Infinity Alpha 1200S is turned on, LEVEL up and other settings set, then there should be a thump or humming sound when the RCA tip is touched. That there is none would make the Infinity Alpha 1200S suspect rather than the absence of a "...signal from my AVR..."

Would you consider a alternate connection? It would serve as both a TEST and as an attempt of a fix.

Customer: replied 5 months ago.
Sure. Any ideas? What would you have in mind?
Expert:  Louie replied 5 months ago.

Connect the Infinity Alpha 1200S's HIGH LEVEL IN R & L terminals to the Sony STR-DE875's FRONT L & R speaker terminals (parallel to the existing speaker/wires connected).

Customer: replied 5 months ago.
Ill have to disconnect the front right speakers i dont have any extra set of speaker wire. Give me a minute.
Expert:  Louie replied 5 months ago.

I understand; no prob.

Customer: replied 5 months ago.
Nothing coming out of the sub still. I disconnected the front right speaker that works and plugged those wires into the sub and still no sound from the sub.
Expert:  Louie replied 5 months ago.

It would appear to be an internal hardware issue.

Are you then considering a DIY (do-it-yourself) repair approach? If yes, do you have access to and familiar with a multi-meter and even a soldering iron?

Customer: replied 5 months ago.
I dont have either. Are you saying the sub is bad or the AVR is bad..
Expert:  Louie replied 5 months ago.

Based on the results of the above tests, it would most likely be a faulty sub.

Still, do you have a CD player, or portable MP3 player or even just a 3.5mm-to-RCA plug cable?

Customer: replied 5 months ago.
I have a Bose speakers that I can plug in from a phone. Is that what you are referring to??
Expert:  Louie replied 5 months ago.

Actually, I was hoping to validate if not confirm (more) the likelihood of a failed sub by connecting the sub's R & L jacks LINE LEVEL IN to the AUDIO OUT jacks of a CD player, or portable MP3 player or even the earphone/headphone jack of a phone.

Customer: replied 5 months ago.
I have a red & white audio cables or a coaxial cable or a cable that goes from a phone to speakers. I dont have the cable you send me an example of though.
Expert:  Louie replied 5 months ago.

Yes please; any connection/means that can feed another sound source to the sub's R & L jacks LINE LEVEL IN. The idea is to try make any sound come out of the sub without connecting/using the Sony STR-DE875.

Customer: replied 5 months ago.
what do you want me to connect the audio cables to as an sound source??
Expert:  Louie replied 5 months ago.

Any device that has red & white jacks for AUDIO OUT such as an old cassette deck, a CD player, DVD player, cable box would serve the purpose.

Customer: replied 5 months ago.
one sec..
Expert:  Louie replied 5 months ago.

When able; thanks.

Customer: replied 5 months ago.
I happen to have another Onkyo receiver but I dont have an antenna to get a signal. Got any ideas on how to get some type of sound to come out of the Onkyo AVR???
Expert:  Louie replied 5 months ago.

Any length of electrical wire would serve as an FM antenna. If available, then the Onkyo could test the sub while in FM mode.

Customer: replied 5 months ago.
K. I got a cable and a channel. What Audio output should I use on the back of the receiver, Phono?
Expert:  Louie replied 5 months ago.

What's the Onkyo's model number please?

Customer: replied 5 months ago.
TX-SV70PRO
Expert:  Louie replied 5 months ago.

Please connect the sub's R or L ***** *****NE LEVEL IN to the Onkyo's MONO OUT (SUB WOOFER)

Customer: replied 5 months ago.
one cable to the Subs R or L or both red and white cables to the R & L Line Level of the Sub?
Expert:  Louie replied 5 months ago.

Just 1 cable please...

Customer: replied 5 months ago.
I have the red cable of the audio cables connected to the Sub woofer (phono out) to the R of the Line level of the sub. NOTHING..
Customer: replied 5 months ago.
The red light of the sub has always stayed red and never turned Green indicating that its receiving a signal..
Expert:  Louie replied 5 months ago.

Sorry but not phono out but MONO OUT (SUB WOOFER) to the r or L jack of the sub's LINE LEVEL IN.

Re-check with the Onkyo tuned to an FM station, sound playing on the speakers, Infinity Alpha 1200S turned on and controls set to MAX GAIN

Customer: replied 5 months ago.
Nothing. I even took some extra speaker wire and ran it from the Onkyo to my other center speaker and it worked. I think tried to do the same with the sub and nothing. The red light is still on and the sub isn't receiving any signal..
Expert:  Louie replied 5 months ago.

I checked the repair / Service Manual for the Infinity Alpha 1200S and yes; there is a separate circuit for detecting incoming audio signals that then triggers fully turning on the built-in amp for the sob speaker.

This would confirm the internal hardware issue.

Are you then considering a DIY (do-it-yourself) repair approach?

If yes, do you have access to and familiar with a multi-meter and even a soldering iron?

Customer: replied 5 months ago.
I dont have either. I am willing to get both. Where can I get a multi meter?? Home Depot or Lowes?? Do you think this is something that is correctable?? I would like to do the DIY route just not sure where to start.
Expert:  Louie replied 5 months ago.

To my understanding, both offers multi-meters of different brands/models. Nothing in particular as long as it can read resistance, AC and DC voltage.

Customer: replied 5 months ago.
once I get those then what?? It will be tomorrow at the earliest.
Expert:  Louie replied 5 months ago.

Then I can provide troubleshooting steps; i.e. which part to test.

Customer: replied 5 months ago.
ok. I will email you back when I have the tester and soldering iron..
Expert:  Louie replied 5 months ago.

Great on the DIY!

Customer: replied 4 months ago.
Louie, If I get the sodering gun and meter can you help me fix the subwoofer tonight??
Customer: replied 4 months ago.
Hello....
Expert:  Louie replied 4 months ago.

Sorry for the delay; mobile with sluggish Internet if at all.

Still, please post back with clear pictures of the internal circuit of the subwoofer. Click HERE.

Thanks.