Bose radio/cassette

[boscojr1]

I have an 89 coupe that has develoved a buzzing noise coming from the passenger side door speaker. It's present when the radio is on and/or the cassette player is in use. I have checked the connections on the speaker and they appear fine. Its frequency seems to follow the engine rpms.

Anybody have a similar experience or thoughts on trouble shooting and possible fix? Thanks for the help.

Jacque "Jack" Evans

 

[paintdaddy]

I have the same problem but its not that bad yet.I think it either has something to do with the volume knob or a factory noise suppressor.Wiggle the knob next time and see if it changes.Hope I helped.

 

[Eagle85C4]

The speakers have their own amplifiers and when the buzzing starts it usually means the capacitors in the amps are starting to go bad. There are several places you can get them repaired or buy replacements. EBAY is a good place to find replacements. I also repair the amps....let me know

 

[c4ever]

;stupid

Carlo

 

[SPANISHVETTS]

Hey Eagle,

Your spot on. I have replaced the Caps in 3 of my amps. What a pain in the A$$. ad

I just replaced the 4th. one. It looks like it had some humidity damage so I plugged in a new one. If I send it to you will you have a look at it? With my Bose history it never hurts to have a spare.

 

[Eagle85C4]

Not a problem...I usually repair stuff for CAC members for parts cost and shipping. No labor...just doing my part to help folks out. Send me email and I will send you address to send them in to.

Thanks Carlo....not sure what to make of the stupid sign.....


I might add that the parts in the amps usually run around 20% tolerance, I use 2% tolerance parts and also run a higher heat capability. Cost is a bit more but in the long run it is worth it. And I warranty my work.

 

[boscojr1]

Eagle,

Thanks for the reply. Please e-mail me your address and what I need to send etc. for the repair to the speaker. I will send it to you on Monday. My e-mail is jcevans@inebraska.com

J. Evans

 

[c4ever]

Jack,
I don't know if you're aware but removing that spk/amp is worse than pulling teeth. Just thought I'd prepare you. I received this information from a good source (NYERNGA, AKA Len) Maybe he'll chime in.

carlo

 

[silver 80]

Eagle85C4,
can I inqure why you use 2%? I'm just wondering that's all. trying to learn something here.

 

[Eagle85C4]

Capacitors are either used to charge and hold voltage or for use as a filter, taking unwanted frequencies and sending them to ground. The ability for them to work is very dependent upon temperture. As the temp fluctuates so does the value of the cap. As the value changes so does the frequency being filtered change. Now if you use 20% tolerance, the value under ideal conditions can sway +/- 20 % of it's listed value, change the temp and you can see an even wider fluctuation in the value of the cap. By using 2% components you limit the the amount of sway, keeping the cap closer to it's intended engineered value.

 

[silver 80]

Thanks. makes sense.
I have a spare amp with the green caps and I guess I'll be replacing them, what temp do you recommend? They are @105c now. Would you recommend replacing all of the caps (the big blue ones too)

 

[Eagle85C4]

Well Sir...

If you convert to F °'s , 105 C°=221 °F...that is the coolant temp on a good day, the filter is attached to the rear of a head, between it and the firewall. That subjects the parts to temps at the upper limit. Not meant to operate there for extended periods of time. Not much airflow there. As an engineer I was always told when you design, "tell them it will work at 100%, then design it at 150%"....I would go more towards 300°F or 150 °C....gives you a bit of lateral movement so to speak....