suggestions on radio repair - ZR-1 Net Registry Forums

mlipmd · 06-24-2021

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 · 06-24-2021

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!

cadillac531 · 06-24-2021

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 · 06-24-2021

Quote:

Originally Posted by 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?

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!

mlipmd · 06-24-2021

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 · 06-24-2021

Quote:

Originally Posted by 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.

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.

dredgeguy · 06-25-2021

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 · 06-25-2021

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 · 06-25-2021

Quote:

Originally Posted by 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.

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

bowtiguy · 06-25-2021

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.

06-24-2021	#1
mlipmd Join Date: Mar 2021 Location: Crawfordville, FL Posts: 201	suggestions on radio repair 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. Last edited by mlipmd; 06-24-2021 at 03:13 PM.

06-24-2021	#2
TX '90 ZR1 Join Date: Oct 2017 Location: TX Posts: 1,956	Re: suggestions on radio repair 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! __________________ Kenny 1990 #442

06-24-2021	#3
cadillac531 Join Date: Jul 2005 Posts: 243	Re: suggestions on radio repair 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? __________________ Constantine Registry Founding Member #0235 1991 Corvette ZR-1 -- Stock, 94 ZR-1 exhaust system, muffler delete. 1956 Chevrolet Belair -- Pro Street, 531ci Cadillac, 8-71 Blower, 8pt roll bar, built TH-400, 9" rear, 1,100 HP -- Street Car. https://www.youtube.com/watch?v=z8y4cwcvK0s 1968 Mustang "Pegasus" -- Zeeker Chassis, 584ci Dart Block, Brodix Big Brodies, 2-1150 Dominators, FTI 'Glide, 1168 hp, best ET & Trap(holding back) 8.57@159 -- 7.9X -- 1/4 mile car. 1970 Chevelle -- 468ci, TKO600, shaved and smoothed everything.

06-24-2021	#5
mlipmd Join Date: Mar 2021 Location: Crawfordville, FL Posts: 201	Re: suggestions on radio repair 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.

06-25-2021	#7
dredgeguy Join Date: Aug 2012 Location: Ellicott City, MD Posts: 1,634	Re: suggestions on radio repair 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 __________________ Charlie __________ Dredgeguy WAZOO Member 1992 Bright Red/Black ZR1 #246 Dana 4:10 gears Polished LT5 by Haibeck Polished Fikse FM5's with Michelin Pilot Sport 2 Stainless Works headers and cats with Corsa

06-25-2021	#8
mlipmd Join Date: Mar 2021 Location: Crawfordville, FL Posts: 201	Re: suggestions on radio repair 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.

06-25-2021	#10
bowtiguy Join Date: Aug 2005 Location: Cali-rodo Posts: 270	Re: suggestions on radio repair 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.