The BOSE Prototype that Never Made It

Mark tries to fix a very rare prototype radio, bought in by Ralf of the DCC Museum (check out his channel @DRDCC ) which combines a SONY Mini Disc Changer, and PHILIPS Digital Compact Cassette! This prototype was built by DELCO ELECTRONICS in 1995, and we don't know if it ever worked!
There is, of course, no documentation or schematics to help us out. We spent a long but fun day together, trying to see if it could be bought back to life! We didn't start filming until 8pm, so forgive the quality - we were quite tired.
Be sure to check out the DCC Museum for more rare examples:

[bobgrob]

Mark, we need a part 2. It can't end this way!! It can't end this way, Mark! You can do it, Mark!! Have him leave it with you.

[DRDCC]

Thanks Mark for a great day and all your efforts trying to make this work for the DCC Museum.

[silberware]

A Theftlock feature is probably looking for an unlock code. This was popular in the 90s, discouraging theft by rendering the unit useless if disconnected from power without knowing an individually assigned code which is entered thru the preset buttons to reenable functionality. The Nakamichi TD1200 was one of the first products to use this scheme.

[maligi]

Mark you are a real man. Because you have patience and only with a smile on your face. Success! I enjoy following your work.

[jeremythejetplane]

Hey Mark, a couple of comments on this. In my experience the 8v rail is very common in car stereos; it's often used for the tuner and audio processing (e.g. volume/tone) sections. The display driver IC is an Oki MSC7170 - also a common part in car audio. It includes button inputs so also often handles the button matrix as well. Datasheets are readily available if you search for the full part number.

I thought this was a very interesting job to take on, thanks for posting the video even if it didn't work out!

[sparkybruce]

Your PSU is current limiting which might be causing it to crash during power up. If you swap over to the 25V 4A config on the PSU you can run it with a 12V @4A current limit to see if that helps.

[XMguy]

I hope for a part 2. I want to see this working. Great video.

[TheBelcherMan]

Only been following you for a month or so and didn't expect that ending.

Just looking at it, might be one of the most complex pieces of kit I've ever set eyes on? I think you made the right call and called it a day. For that matter, so did the Bose axing the project.

[eddieMurphy]

enjoyed the video again i am just trying to remember everything i was taught before my stroke so a wonderful video thank you

[fretlessfender]

That was just a pleasant surprise to see Ralf pop up in your video! I am a member of the DCC forum and a massive fan of you Mark... so seeing you both together was someting else!

[Yorumcu]

Mark
You have great videos. You have excellent knowledge and experience.Congratulations.
You wrote on your website that you were busy for several months due to repair requests.
You can ask your customers "Do you want a video to be taken during the repair?" If the customer says "I want", you can ask for an extra fee.
You are already very patient and work very professionally in repair. Your customers will also see how much effort is put into them.
In addition, these videos are also useful in youtube videos.
Regards
*Translated with google translate

[valpine]

Make sure you reconnected the red (key switch) power wire after you corrected the front panel ribbon. The radio won't do anything without both yellow (constant) and red (switched) inputs. I'm sure it's nothing that simple though and you already figured that much. Ribbon was probably upside down from previous trouble shooting attempt. I'd focus on that burnt transistor, maybe the transistor is good (or not) but whatever it's powering and possibly what feeds it isn't good for sure.

[Big_ol_bass]

We need more videos Mark, absolutely love them!

[brianp]

Wow imagine having that unit in your car back in the 90s …looks like it was mega expensive!

[rafi]

Great to see you 2 guys together. Greetings from Poland

[tnito]

I know it's a stupid basic question but it wasn't shown in the video, did you redo the battery + ignition connection? Because I was under the impression you left the battery wire only to see if there was still current draw.

[Vchat]

The theftlock writing on the front plus being Delco is a dead giveaway that this was likely a GM component here in the states. The power draw may be a red herring as GM vehicles even back around this era passed all the bings and bongs from things like lights being left on, key in the ignition with door open, etc. through the headunit so the amp circuit was probably legitimately active for this purpose.

I was going to make a comment about possibly needing some digital 'ignition' signal to turn on but I'm not 100% sure if they used this methodology back then. It's more common now however with CAN bus based vehicles.

EDIT: Doing some more research bears out the last point. Looks like GM vehicles of this vintage didn't have a traditional voltage based ignition signal but was all data based. So this unit is likely looking for a digital signal from the vehicle telling it the ignition is on. GM-LAN is the protocol used so that may help if you want to try to rig up something to fool it.

[eaglevision]

My father had a Cadillac Seville STS that was a re-import from Japan. It had this exact radio with the MD Player.

[Capturing-Memories]

What a gem! A MD changer and a dcc combo? wow. I hope you guys manage to get it going in the future, I want to see the MD changer in action.

[trevorwhalley]

Dear Mark. I don’t use telegram, this video about BOSE, and your previous one on B&O, shows that both are quality goods, its really. nice that you invited a guest, gave hospitality, and admitted ( understandably) components you don’t know of beat you, your magnetic personality does you well, keep making the vids, they are so interesting and entertaining.Trevor