suggestions on radio repair

[mlipmd]

As is typical, on my '90, the radio was non-functional when I got the car, most likely due to leaking 31 y.o. capacitors. The head unit itself seems operational because the antenna goes up and down, the clock works, AM/FM works, stations can be selected and scanned, the cassette works and ejects properly but no sound comes out, and I got 12V at the speaker wires, so I don't think that or the computer under the PS dash is the problem. I removed all the amps and 2 of them were badly burned probably from leaking caps causing a short on the board, and they were sent to Bose Central in FL for repair. 3 of them were repairable i was told, one beyond repair and needed replacement with one of their refurbished units. I got them back yesterday and hooked them up today and no sound comes out of three of them and only very faint sound out of one in the right rear (which I think was their refurbed one, the other 3 my originals). I have contacted them but have not heard back yet.
What do you think is the likelihood that it is the CDM under the PS dash as the problem? From what I have seen online, that is a real PIA to get out and I really don't want to do that if I can avoid it.
Has anybody else had experience with Bose Central?


Edit - Just got a call from Kurt at Bose who swears it is the CDM now causing my problem. It has the same old capacitors that also can leak inside that unit so he wants me to pull it and send it in to him for repair. They also have new ones and I just may bite the bullet and get one of those so I don't have to fuss with this again. He says he got those new units from Bose and the capacitors are good despite their age because no juice has flowed through them and it is the heat from use that makes them leak. Sitting on a shelf for all these years according to him, does not damage them. Any thoughts about any of this?

Stay tuned.

[TX '90 ZR1]

Dollars to do-nuts, I bet it's the "computer" under the dash. CDM or DCM it is called. Never can remember which!
I've used Dr. Don and have nothing but good to say about him. No personal experience with the other place, but have heard they are good also.
If you have to take it out, do a search for CDM (DCM) removal and also post up here on the forum. A lot of us have removed them and will give you some pointers as well as moral support which you will definitely need!
:cheers:

[cadillac531]

When speaking to Dr. Don today, he was telling me the radio module is behind the passenger seat and not very hard to get to. That may be what your issue is. Did you look there?

[TX '90 ZR1]

When speaking to Dr. Don today, he was telling me the radio module is behind the passenger seat and not very hard to get to. That may be what your issue is. Did you look there?

Unfortunately, the '90's are in the passenger side of the dash. Later years, not sure exactly when, were moved to the compartment behind the passenger seat.
I bet some GM employee had to remove one and raised so much hell they decided to move it!
:cheers:

[mlipmd]

I'm thinking of getting a new unit from them (see edited post above) so when I remove the old one, I already have another in my hand so I can remember how to replace it.

[TX '90 ZR1]

I'm thinking of getting a new unit from them (see edited post above) so when I remove the old one, I already have another in my hand so I can remember how to replace it.

Read your edited post.
Not to doubt anyone, but I would be inclined to get a second opinion on using a 30 year old unit, used or not. I was always of the understanding that the problems were more a function of age instead of use. If not, why do a lot of the really low mile cars have non-functioning radios?
Believe me, you do not want to remove the unit but one time.
:cheers:

[dredgeguy]

Get it repaired or replaced by Dr. Don....he is the man when it comes to Bose. Do yourself a favor and send him the head unit and have him put an aux input on it so you can plug in a XM radio or your phone for perfect clear sounds and still retain the stock look

[mlipmd]

I believe you guys are right - I am going to get my CDM repaired (with new caps) rather than relying on ones that are NOS but 25-30 years old.
Going to dig mine out today and dreading it, but that's the only way to fix it and keep it original.

[TX '90 ZR1]

I believe you guys are right - I am going to get my CDM repaired (with new caps) rather than relying on ones that are NOS but 25-30 years old.
Going to dig mine out today and dreading it, but that's the only way to fix it and keep it original.

:thumbsup: I believe this is the wise and correct decision. Good luck.
:cheers:

[bowtiguy]

I had a full Bose rebuild done on my 91 NCRS car for $700 through https://www.carstereohelp.com/ 2 years ago, but he is closing for the summer 2021.

Dr. Dons turned around the complete system on my current car in quick order, but it was $1100 including the aux input.

[Young1]

Factory Car Stereo Repair
Bob is his name, easy to work with
(407) 830-0777 Work
(407) 304-6460 Mobile
Specializes in old Bose

1480 Oberlin Terrace
Lake Mary FL 32746
United States

I just took everything to him to check it all out. What worked I took back home. What did not stayed with him.

CDM and head unit repair was around $400.00

Removing and replacing the CDM requires an ocean liner load of patience.

Drive the car to Bob and have him remove it.

[mlipmd]

I took it out today, a ridiculous job, and just hope I can get it all back together again and that everything works afterwards.

[TX '90 ZR1]

I took it out today, a ridiculous job, and just hope I can get it all back together again and that everything works afterwards.

:thumbsup: Congratulations. Good job!
:cheers:

[mlipmd]

Well I went with bosecentral.net (in mid Florida) and it took a while, probably my fault because first I sent the 4 speaker amps, then the CDM, finally the headunit, rather than removing everything and sending it all at once. I dealt with Kurt Boothman who was extremely helpful and caring with numerous phone calls re:status of repairs and recommendations, etc, in getting this back together in working order. So after getting upgraded speaker amps, an upgraded CDM, new CD mechanism and belts for the cassette player, I got it all back together, and I must say, it sounds Great. I highly recommend Kurt and the rest of them and their prices are significantly better than other shops around and they do good work. Very happy now, but what a PIA to get that out and then all back in.
I don't know if any aftermarket unit would sound any better than this Bose system, and with my aftermarket exhaust it would probably be a waste of money too.