Do-it-yourself Bose amp repair

[mxr662]

Does anyone know which capacitors need replaced in the Bose amps or has anyone tried to do this themselves and had good results. I would like to get rid of the whining in the rear speakers, but not really interested in spending $250 to get my amps repaired. Thanks

Andy
Modified by mxr662 at 10:52 PM 3/6/2007

[Raxephon]

Replace them all.

Its tedious, and time consuming.

But the parts are cheap and you'll probably learn something along the way.

[Q45tech]

The early 90's electrolytic capacitors used [as all do have a finite life based on heat/cold cycling]. The ones you don't change will fail soon after replacing the others.

[infinitinut2]

I seem to recall Bose/Infiniti warranting early Q's amps due to "fire danger", or some such. I recall sending mine to Bose, and them either repairing them, or sending me new ones. Quick R&R of them, too. Greatly improved the sound once new ones installed. Just wish I could remember if I did the R&R, or dealer!!! (Senior moment, I guess!)

Perhaps someone else recalls this issue.

[lino]

You can always call these folks:

http://www.carstereohelp.com/strinfiniti.htm

The guy that runs the place is super nice and may help you out. I think his name is Jerry, not certain though. He's very friendly, knowledgeable and worth making the call to.

Good Luck and let us know if you're successful with the repair.

[Q451990]

I seem to recall Bose/Infiniti warranting early Q's amps due to "fire danger", or some such. I recall sending mine to Bose, and them either repairing them, or sending me new ones. Quick R&R of them, too. Greatly improved the sound once new ones installed. Just wish I could remember if I did the R&R, or dealer!!! (Senior moment, I guess!)

Perhaps someone else recalls this issue.

It was the rear amps only... if I recall correctly 91 & 92 model year. Bose did a courtesy rebuild of my fronts (I have 91 amps in my 90 - long story) due to the recall on the rears. Not sure if they're still doing that or not.

Heath

[lino]

Call Infiniti USA and see if there is an open recall on your car by supplying them with your VIN. They will tell you if the recall has been performed or not. They will honor the repair at any time as it is a saftey recall.

Here are some websites that describe the recall:http://www.automallusa.net/199....html

http://www.autorecalls.us/aut-....html

[texasoil]

we just did this on spouses 92a--left front door started screeching at 120dB. the 2 large capacitors on the board need replacing. They were 820 uf@16VDC. We replaced them with 1000uF@25VDC, 95C temp. Be sure and get the 'high temp' capacitors for increased durability. Parts cost<$3.00, time less than 1 hour R&R +repair. 1 hr for finding the parts.

[maxnix]

There is a TSB on the recalls for 1991.

[mxr662]

My Q is a 1990. The recalls I've seen apply to 91 and later.

[mxr662]

Ok so I went to http://www.carstereohelp.com/s...e.htm and used there guide to remove one of my rear amps. Carstereohelp.com is a great website. I will have them repair my amps if I am unsuccessful repairing them myself.

Amp Removed

Modified by mxr662 at 10:13 PM 3/7/2007
Modified by mxr662 at 10:31 PM 4/1/2009

[qsiguy]

........They were 820 uf@16VDC. We replaced them with 1000uF@25VDC, 95C temp.....

So no noticable change (good or bad) by using a slightly different part? Notice any difference from the left to right? I suppose if these caps are just filtering caps on the power supply the difference would be very minor.

Anyone have a schematic of the amps? Oh, and do you remember if they were polarized caps or not?

[mxr662]

I removed the capacitors from one amp. They are 1000 uf 16volt. I have pictures but not quite sure how to post them. Texasoil got me started in the right direction. I am going to try replacing the 2 large blue/grey capacitors.

http://www.q45.org/gallery/v/bose_amp_repair




Modified by mxr662 at 10:35 PM 4/1/2009

[qsiguy]

Beautiful, I forgot about that guide on q45.org. Answers my question as well. They are polarized meaning they have a positive and a negative lead and need to be installed in the right direction.

[mxr662]

I forgot about that guide on q45.org.

That guide is the pictures I took tonight but I can't get them to show up in my post.

[Raxephon]

I removed the capacitors from one amp. They are 1000 uf 16volt.

Thats interesting.

I have the Amp Assy,Front,797) sitting in front of me and it has (2) 820 uf 16v capacitors.

Plus mine dark brown with a white stripe.

The ones pictured below aren't mine.

[Raxephon]

That guide is the pictures I took tonight but I can't get them to show up in my post.

These pics?

[Q45tech]

While you are in there replace the other 7 smaller electrolytics shown as green in picture................just a matter of time as all have been exposed to same temperature and hours of use.

Just a fact of life than low-medium price electrolytics have a short finite life.If you increase the specified rated working voltage you can increase the life span along with their size [limited by fit/space]. Not much point in going above 35/50 volts.

[mxr662]

My image show up when I put the correct url between the image tags. What a concept.

These pics?

Thanks for the picture posting help.
Modified by mxr662 at 10:30 PM 4/1/2009

[Q45tech]

A few sites to help understand:http://www.zr1netregistry.com/Bose2.pdf ... 56634.html

[Raxephon]

A few sites to help understand:http://www.edn.com/article/CA56634.html

Here's the pdf for that page linked above -> http://www.edn.com/contents/images/56634.pdf