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: 12052
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: 10 months ago.
Category: Home Theater-Stereo
Expert:  Louie replied 10 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 10 months ago.
Sony STR-DE875
Expert:  Louie replied 10 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 10 months ago.
Coaxial cable hooked up to the Right side of the line level inputs on the back of the sub.
Expert:  Louie replied 10 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 10 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 10 months ago.
Did you get my question??
Expert:  Louie replied 10 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 10 months ago.
Touch it with what?
Expert:  Louie replied 10 months ago.

Touch the RCA tip with your finger.

Customer: replied 10 months ago.
Ok. I touched it and no sound period or noise.
Expert:  Louie replied 10 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 10 months ago.
Sure. Any ideas? What would you have in mind?
Expert:  Louie replied 10 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 10 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 10 months ago.

I understand; no prob.

Customer: replied 10 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 10 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 10 months ago.
I dont have either. Are you saying the sub is bad or the AVR is bad..
Expert:  Louie replied 10 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 10 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 10 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 10 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 10 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 10 months ago.
what do you want me to connect the audio cables to as an sound source??
Expert:  Louie replied 10 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 10 months ago.
one sec..
Expert:  Louie replied 10 months ago.

When able; thanks.

Customer: replied 10 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 10 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 10 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 10 months ago.

What's the Onkyo's model number please?

Customer: replied 10 months ago.
TX-SV70PRO
Expert:  Louie replied 10 months ago.

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

Customer: replied 10 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 10 months ago.

Just 1 cable please...

Customer: replied 10 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 10 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 10 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 10 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 10 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 10 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 10 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 10 months ago.
once I get those then what?? It will be tomorrow at the earliest.
Expert:  Louie replied 10 months ago.

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

Customer: replied 10 months ago.
ok. I will email you back when I have the tester and soldering iron..
Expert:  Louie replied 10 months ago.

Great on the DIY!

Customer: replied 10 months ago.
Louie, If I get the sodering gun and meter can you help me fix the subwoofer tonight??
Customer: replied 10 months ago.
Hello....
Expert:  Louie replied 10 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.

Related Home Theater-Stereo Questions