Hey guys,

it's been a few months since I've been active on here, but as the year winds down, I'm hoping to get back to some of my projects. I did some picking back in October and picked up a stock S5 radio with the intent to repair and restore it, and eventually do a bluetooth conversion on it, as mentioned in some of the other threads on here. I'm hoping there are some of you on here that have messed with these, and can help me get it going. I did get ahold of the Pioneer repair manual from ebay, surprised I could find such a thing, and am trying to figure out how to digitize it. It has quite a few large foldout diagrams that would require a large scanner, while the rest is just 2-sided 8.5"x11". The price to get it scanned at Staples or similar would be about $160-200...

Anyways, I pulled the radio and amp unit out of an S5 vert, so the AE unit has 1 button instead of two, but from what I'm seeing, that really shouldn't make much of a difference. The unit was in pretty poor shape when I pulled it. Rust was present on the steel brackets and shell. There was significant weathering on the screen, the buttons were full of finger crud, and mud-dobber nests and dead spiders had to be evicted after I opened up the shell.

Upon inspection of the boards, the most noticeable items were the electrolytic caps, many of which were swollen and leaking. I then proceded to recap the unit. I replaced all the electrolytic capacitors in the unit with the exception of the bipolar and polymer caps because they tested fine. I tested all the capacitors I removed as well as the ones I replaced them with and documented them by their board and number. Many more capacitors had failed than were visibly obvious.

After replacing capacitors, I cleaned up the buttons and front panel. I restored the screen so it looks clear. I reassembled the unit and plugged it into my car. The lights on the unit came on with the key powered on. I'm not sure if it is supposed to light up automatically or not, hopefully one of you guys can tell me. A couple of random segments showed up on the LCD screen for a few seconds before going dark again. The unit didn't respond to any inputs, nor would it take a disc or tape. No sound was produced, other than the pop of putting power to the speakers. The antenna did go up automatically when the unit was grounded.

I took the unit back apart, and found a couple things. There were a couple of shorts in power board the board that takes 12v ACC and BACKUP power. There was a solder short up near where the ACC, +5v, and GND connector goes to the CD board. I removed and resoldered all of those joints. I don't think there was a chance that 12v got into the 5v pin, I didn't find any hot spots on the CD board either. After that short was fixed, another short showed up at the long connector that mounts the power board onto the main control board (U shaped board). In that case, ACC was arcing to GND, and burned the board in between. No idea how this short started. I didn't work near either connector location. Anyway, I dug out the burned carbon between the traces until there was no more continuity, and filled the hole with some RTV black for some insulation and heat resistance. I haven't tested it yet, but if any of you guys have some idea of how to get this thing working, I'm all ears.


Unit as I obtained it.

Unit after I cleaned it up

Arc'd short located between ACC and GND filled with RTV

 

I met with some success last night. I was able to get some segments of the LCD to show up weakly, although no back light. I'm getting voltages on some pins that should be dead ends, so again, I'm still just picking away at the power distribution board. I've got the 5v and 12v outputs going correctly, but I also have 2.5v showing up on pins that aren't connected to anything as well as very little voltage on the 8.5v output. This has gotta be a goofy diode or something dumb...

 

You're doing better than I could do. A couple years ago, I took our S5TII radio/equalizer to
a local shop, $150 later did an install and all lighting back to normal.
Good luck

 

Starting to think that might be my next move.

 

So you are looking to install Bluetooth (conversion?) into this old radio? How does one even go about something like that? And if indeed it can be done, what about installing a USB (for music) in it as well? I would love to reinstall my (90 vert) OEM radio yet have USB and Bluetooth capability.
Right now I have an aftermarket digital receiver (mini amp connected to it) with all new speakers and a sub with amp in the trunk. So, I like my set up as it it loud and very clear but would love to have that OEM back in it, too. Of course with Bluetooth, USB, etc.

 

There's a few different approaches here. Here is what I did:

https://www.rx7club.com/2nd-generati.../#post12365710

The flaw with my plan is the CD player skips over rough roads. Smooth stuff and it's mostly fine. There may be another adapter that exists that could also do USB.

 

Good luck in your endeavors here. I love the look of these stock units and that definitely cleaned up nice. I hope you can get it working. Getting my Bluetooth up and running is about as far deep as I could ever get electronically on one of these things.

If anyone wants to chip in, I wouldn't mind helping offset some of that cost of getting it scanned if you can't find any other way.

 

I missed that part of your build Jerry, but I like what you did. I'm pretty envious of your build. The idea I had was to tap into the tape deck audio. It is a much simpler mechanism than the CD. I was thinking on having whatever bluetooth gizmo I get ahold of be able to have a parallel trigger with the switch that indicates a tape is loaded, that way I would still keep tape functionality and just have the bluetooth audio work as an interupt whenever audio plays from my phone. They already have bluetooth cassette adapters, so I figured that might be a good place to start. I had thought about figuring out how to put USB into the CD part because then you could possibly figure out how to skip/navigate with the controls, but that's way above my head.

First things first though, I gotta get this thing to boot up... I have no idea where to go with it.

I figured just recapping the thing would fix it. I have recapped everything else and it has worked great. The stock door speaker amplifier has some thump to it after recapping. It just sounds kinda weird because the aftermarket head unit I was using either had amp hi/lo and no dynamic adjustment like the stock units would do. I picked up a couple of S4 rear speaker amp tubs and was going to see how tapping those into the amp line would turn out with some larger speakers. I would just need to run power +/- and an amp line, as the S5 speaker lines are already there. But that will come after getting this head unit up and going.

I was able to clean up the screen using plastic headlight restorer spread on some printer paper. Worked pretty good to lap it to a clean surface again. It worked because the polarized sheet is sandwiched between two layers of plastic, so the restorer wouldn't actually harm the polarized layer.

 

Couple things I want to ask

1. Does the lights come on in your working units automatically when the car is powered on, or only when your marking lights are turned on? Mine are currently stuck on, but just not as bright with the switch off. No LCD lighting yet.
2. Jerry might be able to answer this; Does your screen work with just the power board, the main control board, and the front panel hooked up, or do you have to have the whole thing hooked up to receive any screen output?

 

Found someone who is a lot more skilled than me to get it up and running. I'll keep you posted.

 

Your follow up seems like you've sent it off, but for #1, only when the marker lights are on. Otherwise it is only the LCD screen for station/track/etc.
For #2, I never got that in depth. Thankfully my unit was working. It's the unit from my first RX-7 and the previous owner had it repaired a couple of times (there's a label that says new caps sometime in the 1990s). I took it out of my first RX-7 to go aftermarket, but never got rid of it. When I finally restored the TII, I eventually made the decision to go stock head unit. I'm thankful I kept it all these years - I got my first RX-7 in 1999.

 

I have the same radio and it could sure use a “tune up”. The cassette doesn’t work, the balance and fade ***** are very touchy and the creep is very difficult to read.Is there a shop anywhere who can repair these?

 

Jon,

I'd look for someone who specializes in radio repair and give him plenty of time to work on it. In my situation, I had already worked on the unit, so I was fortunate that I found someone that would take a look at it. Often times, if you have already worked on electronics, a repair shop won't take it. Once I get my unit back, I plan on copying the manual and uploading it so that guys can save it and take it to the repair shops along with their faulty units.

 

I was talking to a guy at a reputable, local audio shop in Fredericksburg (VA). I asked him about hardwiring an AUX as well as a USB, and he said he would likely only do a Bluetooth hookup for me. He told me he knows and understands the reputation of hardwired v. air, but says that he can install a professional Bluetooth unit that is strong enough for serious volume and can sustain a solid, powerful signal. I explained to him that I heard bad things about Bluetooth hookups (weak signals, etc.) but he told me that even the "old" way of hooking up an AUX through an antenna adapter has been phasing out because phones are not coming with AUX jack anymore. I suppose that's probably true, knowing how technology changes so quickly.
I told him I wanted everything else to stay the same: sub w/amp in the trunk, Kicker speakers in both doors and behind the seats (where the two original subs were). The aftermarket Alpine iLX series I put in there came with its own little amplifier, so I'm hoping my old stereo can seamlessly be wired up and work with all the upgrade. I really want my console looking like it did in 1990.
Anyway, we shall see and I will keep posting here as I go through this process.
Almost forgot, I posted in the classifieds here and am looking for some OEM radio mounting brackets. If you have some for sale, I would greatly appreciate it if you let me purchase them from you.

 

I don't plan on going too crazy with this. I don't have the greatest hearing anyway. I recapped the stock door amplifier and got it working. It was driving some Rockford 6.5" speakers in the doors and did a pretty good job of it. The reason I'm wanting to switch back to the stock head unit though is because this amp was meant to be driven by the controller in the stock unit. The aftermarket pioneer I had would only have high or lo amp gain, and wouldn't do the same adjustment as the factory pioneer unit. I had thought about aux and USB, but with BT out now, there's really no need. If I want to play mp3s, I can either burn a cd, or just load them on my phone since it will BT to the unit.

One other point, I don't know if it has been tried. I picked up a couple of S4 rear speaker amp tubs from a vert and recapped them. They have tiny speakers in them, but I was going to experiment and see if they can drive the same Rockford 6.5"s in the rear speaker positions. I would have to run a 12v power, ground, and amp signal wires (or just ground to shock tower below). It might help take some load off of the head unit, I just don't know how it would sound, as I don't know how much it is changed. The AE unit in the S5 setup appears to do a lot of processing and amplification before it gets to the rear speakers, so I don't know how it'll turn out. Just an experiment. Let me know your thoughts

 

Update on this radio.

Got it back from the repair guy, and it was less brain dead than before. Still have a few items to figure out because
1. Button lights are always on
2. LCD is either brightly lit, or off
3. Still a little brain dead, but showing more signs of life than before. I'm thinking it's still a problem with the power board.
He's still working with me to get it right, but wanted to test it in the car.

Jerry, or whoever, can you please shoot me a video of what yours looks like in the car? From key off to key on, marking lights off vs. marking lights on, and LCD illumination under those conditions with the dimmer switch off and on? I would greatly appreciate it. Getting closer, but still need some help

 

I can get you a video in just a bit. Just curious, who did you send it off to? I'm thinking of sending mine off since my Bluetooth mod isn't working as I had hoped. I am thinking of sending it here:

Factory Radio Services and Repair

He can add Bluetooth with a small on/off switch on the faceplate. I'm thinking a 30 year old CD player is never going to be quite right, so I may have to try another option. The tape deck is also in need of repair and it might be nice to have for nostalgia purposes.

 

Hopefully this link works, YouTube says it's still processing, but it worked when I pasted it into a browser. If not, I'll get it fixed. I think my narration explains it all, but if you have any questions, feel free to ask.

 

Thanks for the video. I took it to an AM radio guy that is related to a colleague of mine. He works for himself and I guess since everyone has been stuck at home, he has been working like crazy keeping amateur radio operators in working order.

I bought a couple of wiring harness plugs off of Amazon so we can set up a desktop test rig. Pretty sure it's still a power board issue. With that video, I'll have a better idea of what conditions to shoot for.

As far as the Bluetooth thing goes, I was going to look into that with the thing working. I haven't figured out if the cd or tape drive would be a better place to tap in. Gotta do some studying

 

Right,
so, here's where the repair guy and I are at. The lights on the thing work like they're supposed to (for now), with the occasional problem that they get stuck on when the car is shut off (probably a leaky diode or something). The next problem we are having is that the main controller doesn't seem to be getting any signal. All of the attachments; cd, tape, radio, mechanically try to function, but no signal is transferred. He says it may be a corrupted controller chip firmware, or something similar, but we'll have to keep digging into it. So to recap, we have the mechanical functions, but no actual thinking going on. No reading tapes, no reading cds, no radio signal thru-put.

The next question is, does anyone have a junked s5 cd/tape like this that I could maybe try for some donor parts?

Appreciate the help. Model # on AE unit is DEH-K4141zm

 

Good news! I got ahold of another radio for parts and I have managed to get the AM, FM radios, and the tape deck working. I am still having trouble with the cd drive. Both cd drives and driver boards are throwing the exact same behavior regardless of which pc board I have it installed on. It takes a cd in, spins, then spits it back out. Frustrating, but I'm further than I was.

 

Excellent!
Back in the day, I remember that whole ejecting not long after you inserted the CD as being not uncommon. And I bet there is a typical fix to it.

 

So, an update, I am almost to the point of being able to perform all the adjustments to set up the CD player. There are a few things I still need to do. The first is I need to put an order together to build the signal filters required for adjustment. Most of these filters are described in the regular manual, but there is one, and that one being the most complex, that is only referenced. The manual says that you just use the same filter used in another manual... Sorry Mario, your princess is in another castle... So I got a copy of that one, got the diagram, and will be compiling all this stuff if we get it working. I have copies of a few of the appendant manuals, and will also post instructions on building all the filters, and adjustment procedures. This information is just to obtuse to leave in this form.

To get the CD player in an arrangement so you can work on it, Pioneer has you use some flat ribbon cable extensions, that are no longer available. Well, one is somewhere on the internet, for $180... So I did what any sensible person would do, desoldered the normal connectors from the CD circuit board and soldered in about 1.5' of regular ribbon cable from amazon (~$1/ft), and now have the CD board outside of the main unit and the CD mechanism beyond that so its somewhat spread out and you can at least access it with the tools required. Looks kinda methy, but its my only option at this point.



From here, jumpers are soldered on and off the board, depending on what step of adjustment you are on. I have no idea where the fault lies, so I pretty much have to do them all. In addition to making the filters, I have to jump in my time machine, find a CD burner and some blanks and make a calibration disk. I have the MP3s, but have to put them on a CD. I read that the ones you are supposed to use are precision made test CDs so you can accurately adjust stuff. However, those are rare as frog teeth, and I would also expect one of the later models of CD burners to be able to have a decent degree of precision over something that preceded it 20 years prior.

This unit is putting sound out though. AM, FM, and tape work, although the sound output to the front speakers sounds good, but the volume is underwhelming. The volume output to the rear speakers is miniscule. I had a look at it and found that the AE unit for convertibles was not only different in the buttons on the front, but on the output. I guess the S5 convertible AE outputs a lower level audio to the headrest speaker amp, which then amplifies it back up whereas the couple version outputs hi-power straight to the rear speakers. Per the manual, both of the main circuit boards are the same for both the convertible and coupe and share the vast majority of components. From what I have found, there are only a few resistors and capacitors that are different between the models, most of them related to the faceplate switches. I have the expectation that I should be able to do some parts swapping and be able to convert one of these lo-output convertible units to a hi-output coupe unit, without the side selection, only mute. Let me know what you guys think. My only other option would be to install the two S4 bucket amps that I recapped and run amp power and control to those for higher output (I may do that anyway for MO POWA!!!!)

 

I'm really liking this refurb. Please keep us posted on how things continue.

 

Ok, so brief update.

I've built all the filters needed to adjust the cd player. Im just waiting for the radio guy to come back from vacation because he has the other tools needed to try to adjust the thing. Not all the filter schematics are in the main manual. They did the horrible act of requiring you to find an older manual for a different machine to get the diagram to make a filter. I've got a decent collection of manuals now and will try to get a list together when this is all said and done.

My antenna mast is stuck together, so it only goes halfway up. Any unsticking ideas are welcome. I may just replace the mast if its too much hassle.

I also did some checking on why the radio lights did not dim with the dash and panel lights. Since Jerry's radio did not dim either, I didn't think it was a coincidence. The radio receives illumination 12v signal directly from the rotary switch in the headlight cluster. The panel lights receive a pwm signal from the dimmer circuit that also takes the 12v from the rotary switch. The two run in parallel. I don't know why they didn't intend for the radio lights to dim even though everything else does.

I haven't tested switching the voltage source for the radio, i would expect the button lights to dim accordingly, but I'm willing to bet that th lcd backlight works the opposite way. I'll let you know if I get to that point or if I just leave it.

I did take apart my dash shroud and switch clusters to clean them. They have been sticky with generations of crud, had some dead spots, and I want them smoothly operating and not crusty. I also want to do some 3d printer repair of the shroud. If you want pictures of how those come apart, let me know and I'll post them in a new thread.