I'm not looking to replace so please limit response to helpful response. I have a 1990 coupe. The radio was working fine including the antenna when I put it in storage in October for the winter. I pulled it out last week and the radio is not coming on/the antenna doesn't raise. If you turn it on the screen displays 1:00 and the SVC comes on. I'm not sure if it matters but it has the CD and cassette. The car is 100% original other than replacement parts that I got via contemporary corvette. I checked the radio fuse and it was good. Some people stated there are 2 fuses but I didn't see another radio fuse. Any helpful advice (and no I'm not replacing it unless it's with another 1990 bose). Does it sound like the CDM or the control unit? It's like it has some power as the display comes on and if i hit the set button the green light comes on but nothing else and no sound whatsover.

 

try the ctsy fuse

 

The CDM IS the control unit, do YOU mean by "the control unit" the head unit in the center of the dash? What is the control unit is the CDM, what is in the center of the dash is referred to as the Head Unit.

Each speaker has its own amplifier with (8?) capacitors in them and the CDM also has a number of capacitors. These leak after so many years and not only stop working, but the chemicals may damage the circuit board in the amps, so the speakers may have to be pulled, the amps removed and sent out for repair, as well as the CDM needs removal (Under the PS dash, an absolute PIA). They leak, not because of use but just because of age. The newer replacements are better than the originals.
The problem is not the fuses, especially if you have power to the head unit.
There are a number of reputable repair services for these, (Dr. Dons, BoseCentral, Factory Car Stereo Repair), not your average electronic repair store, and a number of good videos online on how to remove these units (https://www.carstereoremoval.com/htm...alCorvette.htm) so if you want to get this repaired, be prepared to bite the bullet. All the repair guys are willing and able to talk to you and walk you through this and if you search on the forum here you will find all the info you need. My links above cover most of it, so check them out.
And they are not cheap ($50 per speaker amp at Bose Central, to $100+ at the others, CDM repairs $250 at BC to $4-500 at the others).
I had my entire system repaired because I wanted to keep my '90 ZR-1 original, but an aftermarket stereo with bluetooth, navigation, backup camera, etc, would probably been about the same price, and probably sound better too.

 

No luck with the ctsy fuse. It looked fine but replaced it anyway and no change whatsoever.

 

I'm thinking it's the CDM (control data module) or the head unit. It's not the speaker amplifier. I'm sure of it. It's not putting the antenna up. I'm getting some power as it shows 100 on the clock. The SCV comes on when you turn on the radio. The eject works (you can hear it). The stations don't work so to me the logical place is the CDM or the radio head/control unit but this is my 1st problem with it.

 

Right now it may only be the CDM but it's not that difficult to remove the 4 speaker enclosures and take out the amps and send them off at the same time to be checked and/or repaired, as it's only a matter of time until they too crap out.

 

i hear you. All good advice and i appreciate the insight! Its nice to meet someone else that is trying to keep ut all original. Haha. Trying to get through to the Doctor, but it's been busy.

 

Wipers work and I literally checked every fuse. I spoke with Doctor Don the Bose guru and confirmed it's the CDM. He walked me through getting it out. A real PITA project... Anyway it's $250+ $25 in costs and he will turn it around quickly. I'll post once it's up and running. Thanks everyone!

 

Check out the video link I posted above. It'll help you greatly to remove the CDM.

 

Thanks!!!