Bose Lifestyle 12 (no sound)

[GRW]

Help!! my Bose turns on as normal, but no sound out of the speakers, no hum at all even when I turn up the volume. I've checked all connections. The only way I can get sound is by headphones. Yes I know its old but its been reliable. I've done the powering off for 60 seconds then turning back on but no such luck.

 

[Chippie]

Do you have a multimeter?

Does the sound come out at normal levels through the 'phones socket? Does it vary as normal with the volume control?

 

[nike22]

Do you have a multimeter?

 

[GRW]

Yes I can adjust the volume using my remote when using a earpiece. When I turn on the system the volume starts at the default setting.

 

[Sceadwian]

If it's old replace every electrolytic capacitor in it and then try again; or at the very least open it up and post some pictures or there's not way to even guess what's going on.

 

[GRW]

when I'm looking at the capacitors, what signs if any should I be looking for? Sorry extremely clueless here when it comes to electronics

 

[Sceadwian]

Bulging tops or discoloration are common for failed caps. This kind of troubleshooting can't be taught over a forum though. Take pictures with a digital camera, point things out you can see in the real world that you might be concerned by that don't show up in the posted image, and please make sure the images are in focus, lit well enough to actually see and not 5 megabytes each =)

You'll get a LOT more feedback at that point.

 

[mvs sarma]

you could momentarily check the speakers with a 1.5 used cell for thump. You could check for a blown fuse, if any, in the final amplifier stages. you could note down the number of Audio power I C if used and check for DC at the expected input power pins

Caution is needed though to prevent shock etc
PS: In lighter vein, I saw a post and possible reply too at http://forum.ecoustics.com/bbs/messages/1/125990.html where the owner keeps head phone plug in the socket and worries about No sound from speakers.

I would appeal to check for such accidental situation. Of course the OP might well know, being a regular user, that the main audio output to speakers is cut off the moment head phone plug is inserted.

 

[GRW]

I wish it was that easy but I dont regularly use headphones.

 

[GRW]

Pics of my Bose

I took some pictures. I spent a good 30 mins searching for something abnormal looking, but couldnt find anything. Let me know if these are good enough.

 

[Sceadwian]

If the headphone output bypass works you know it's not the input section. It has to be in the final output driver or one of it's intermediary stages (guessing) Which of those connectors on the back panel (highlight something in one of the photos) is actually the speaker out connectors

 

[djabraba]

cording to bose service manual look at ic u101 . in trouble shooting it sid if no volume present change ic tc9163n dip28 part #146814

 

[TWTRTECH]

Unless I am mistaken this Bose unit works in conjunction with a sub woofer module, and that is where the the other speakers amps are located, not in the central unit that you have opened up to take the photos.

 

[audioguru]

Another cheap Oriental sound system.