"Working" OEM Head Unit replaces Pioneer AVIC-X910BT - Now no sound

[tof]

Happy Ending to..."Working" OEM Head Unit replaces Pioneer AVIC-X910BT - Now no sound

Everything on the radio seems to work. Antenna goes up and down with radio power as it should. Casette section seems to work fine. Just one problem. Not a peep, rattle, or hint of hiss from the speakers at any volume. And no music either. All speakers are dead silent.Speakers were working ok with the Pioneer head unit. Pretty sure it was set up to send pre-amp output to the speakers as there was only a harness adapter and antenna connection between the car and the unit. No heavier gauge speaker wires. So I would guess (and its only a guess) that the Bose speaker amps have not been bypassed. So, anything I can do? Check? Open? Close? Switch? Test? I bought the radio from another primer who said it was working fine when he had it, and I have no reason to doubt him. I can't check the connections that were made to the Pioneer because it has gone to a new owner. I paid $400 for this radio and while it looks great and lights up as it should, music would be nice.

 

[Old Guy]

You will need the pin out diagram for the stereo from the service manual. You will also need a single earphone wired up with some bared wires.

Unless you have a bench power supply and antenna arrangement, you are going to have to do an in-car test. Based upon an in-car test, you are going to have to pull out the head unit from the center counsel far enough to give you access to the back connector plugs. The audio signal out to the external amps is on the following terminals (which is why you need the pin out diagram)

Dr side - A2 and A10
Pg side - A1 and A9
Sub - A7 and A15 for one channel and A8 and A18 for the other (the left and right mixing for the sub appears to occur in the sub amp rather than the head unit)

With the head unit pulled out for access; but, the back connectors left connected, power it up and tune to a known radio station. Insert the two wires of the earphone into terminals A2 and A10 using a back probe of some kind (stiff piece of wire). Getting the back probes in to the connector to make contact with the terminals is the iffy part of this exercise. The service manual gives a brief description of using back probes for testing. If you make contact with the A2 and A10 terminals, you should hear the left audio channel. Do the same for the other three pairs of terminals and you should get a corresponding audio signal. If you don't, try the cassette deck (if you can find a cassette) or the CD player if you have one. If nothing gives you an audio signal on any of the channels, I think the head unit is non functional.

The earphone trick is not the best item for doing this type of testing. However, it should respond to the low level signal coming out of the head unit and is probably something that most non technical people have in their possession. A scope would be the best; however, if you had a scope you would be a closet techie and probably would not be asking this question.

Good luck with it!

 

[tof]

Thanks, Old Guy.First thing I am doing is taking the car over to a trusted audio shop. The owner is a former NSX owner and he knows the bose system. We are going to start by checking to see if the Bose amps in the door speakers and subwoofer were bypassed to accomodate a high level output signal from the Pioneer head unit. I need to know this right away so I can advise the person I sold the head unit to as to whether or not he needs to rework the adapter cable that went with the Pioneer. (The Pioneer did have a provision for pre-amp out as well as a 50W/ch power amp output. And I shipped the unit and the adapter cable off before checking its configuration. Dumb, huh.)

If, in fact, the speaker amps are not being bypassed, I will pass on your sage advice. Now all I have to do is find a pinout diagram for the NSX "radio".Thanks again.

 

[Old Guy]

Now all I have to do is find a pinout diagram for the NSX "radio".Thanks again.

You should be able to get the pin out diagram from the on-line version of the electrical portion of the service manual that is linked in the NSX wiki maintenance section.

Edit:

Forgot that I had a .pdf version stored. Here is a screen grab of the pin out. Iffy resolution. If it is hard to read you will have to down load the original.

With luck you just have by-passed amplifiers.

 

[tof]

Thanks for all your ideas and for posting the diagram, OG. I ended up taking the car to a trusted mobile audio shop owned by a former NSX enthusiast (He had a 10 second car! I've seen the car and the time slips.) Anyway, a scope on the output pins showed no real signal...just a bit of noise. The good news: The wiring all tested good for continuity and when we took the speaker housings apart the amps looked brand new with absolutely no sign of damage.

So now I have to figure out what to do about an OEM head unit. There are some ideas in this forum and on a Prime Wiki that I want to look into. Of course any further advise from you or others in this thread would be welcome.

- - - Updated - - -

Oh, btw, what the heck is that "short connector" that looks like it plugs into the CD changer input?

 

[GraemeD]

So now I have to figure out what to do about an OEM head unit. There are some ideas in this forum and on a Prime Wiki that I want to look into. Of course any further advise from you or others in this thread would be welcome.

My head unit died just like this last week, so I am also looking into repairing it. My bet is it is the output circuit has some damage. Hopefully Kaz will chime in, as I have seen where he has repaired a few in his blog.

 

[tof]

I've also run across Kaz's blogs in my research. Why do the Brits get him? We need him here in Mer'-i-ka!

If I find a repair solution I will post it here.

 

[Speedmaster]

I've also run across Kaz's blogs in my research. Why do the Brits get him? We need him here in Mer'-i-ka!

If I find a repair solution I will post it here.

My brother in law...lives on Rodenburg, could be your guy. If you can convince him to start repairing again. (Sadly he is out.)

 

[tof]

Update. I talked to someone at Alpine in California and they said they would attempt to repair it or possibly exchange it. Off it went last week, along with a check for around $248. Fingers crossed.

If they do get it working (or discover it is working just fine and the problem is elsewhere) I will start a new thread appropriately titled so others can take advantage of this program that I stumbled across.

 

[Speedmaster]

Good call. I wondered why Alpine would not do the work in the first place.

 

[JD Cross]

Update. I talked to someone at Alpine in California and they said they would attempt to repair it or possibly exchange it. Off it went last week, along with a check for around $248. Fingers crossed.

If they do get it working (or discover it is working just fine and the problem is elsewhere) I will start a new thread appropriately titled so others can take advantage of this program that I stumbled across.

I've been trying to connect with Alpine Canada (Gentec Ltd. here) but so far no response to my entreaties.
We will be tenacious until we get a yea or nay from them and I'll report back.

 

[Kaz-kzukNA1]

Addition to your head unit, you may want to check your speaker relay and its wiring as well.
As your antenna/aerial goes up, at least the ‘switched +B’ power is generated through the head unit so could be nothing wrong with your speaker relay/wiring but if the relay was activated, you should still hear faint hissing noise from the speaker even without the pre-amp signal from the head unit.
I get the same hissing noise when testing the head unit/amp/speaker on the bench even without connecting the pre-amp signal into the amp.

On our NSX head unit, the switched +B is shared between the Antenna and the AMP power control (thus, the antenna goes up regardless of the head unit mode radio/cassette/CD) whereas on the aftermarket ones, they are normally controlled separately so there could be some modifications done on your original loom.

By the way, not sure this is the same for US model but the pinout diagram of the head unit should be on the bottom lid of the head unit itself.


Kaz

 

[tof]

I've been trying to connect with Alpine Canada (Gentec Ltd. here) but so far no response to my entreaties.
We will be tenacious until we get a yea or nay from them and I'll report back.

You might try Alpine Electronics of America in Torrence, CA
Contact inf at http://alpine-usa.com/company/contact
Maybe they can direct you to a better contact in Canada.

 

[JD Cross]

You might try Alpine Electronics of America in Torrence, CA
Contact inf at http://alpine-usa.com/company/contact
Maybe they can direct you to a better contact in Canada.

I know you're working with Alpine US so I thought I'd try the Alpine Canada folks.
I'm not hopeful.
Hopefully you'll get a rebuilt unit through the US group and if you're satisfied we can all use Alpine US.

 

[tof]

Thanks, Kaz. Great information from one of the most knowledgeable of Primers.
We did find an issue with a relay and when we swapped it out with another in the same bank and we got power at the door amp (iirc).

We did get some faint hissing from the door speakers with the radio turned on and we did see some noise at the door amp low signal connectors on the scope. (again, IIRC). This was WITH a known good relay in the amp relay socket. IIRC (again) the antenna extended when the radio was powered on, regardless of the mode (radio vs. cassette.) I know for certain that when the aftermarket head unit was still in the car, the antenna was always up when the ignition was on. (The head unit could never be completely powered off. The touch screen always had power when the ignition switch was on.)

 

[nigel]

There is a company that does NSX radio diagnosis and overhauls but I don't have my paperwork with me so...
I have two heads in need of sorting and I know they do the work, I just can't remember their name or location right now.
Maybe BrianK has their name?

Cheers
nigel

 

[tof]

Just talked to customer service at Alpine. They are returning the unit to me today as non-repairable. Capacitors have leaked onto the main board. So, $25 down the drain for diagnostic service plus the $23.14 it cost to ship the unit to them.

Nigel, if you run across that company I would be interested to know. If it is Williams Electronics, they are generally not doing repairs any more. They do sell a conversion where they replace the guts and display with another system while retaining the OEM exterior and front panel but the cost is *gulp* $870. I'm thinking about it but none of the original front controls are used except the volume knob which is converted to a sort of joy stick.

 

[JD Cross]

Just talked to customer service at Alpine. They are returning the unit to me today as non-repairable. Capacitors have leaked onto the main board. So, $25 down the drain for diagnostic service plus the $23.14 it cost to ship the unit to them.

This is disappointing tof.
I was really hoping Alpine would come through for you (and us)
The leaking capacitors sounds like the same thing Speedmaster ran into when his repair guy said it looked like someone had spilled coffee on the head unit.
If we are all sooner or later facing an unrepairable head unit what do you see as a solution?

- - - Updated - - -

Addition to your head unit, you may want to check your speaker relay and its wiring as well.
As your antenna/aerial goes up, at least the ‘switched +B’ power is generated through the head unit so could be nothing wrong with your speaker relay/wiring but if the relay was activated, you should still hear faint hissing noise from the speaker even without the pre-amp signal from the head unit.
I get the same hissing noise when testing the head unit/amp/speaker on the bench even without connecting the pre-amp signal into the amp.
On our NSX head unit, the switched +B is shared between the Antenna and the AMP power control (thus, the antenna goes up regardless of the head unit mode radio/cassette/CD) whereas on the aftermarket ones, they are normally controlled separately so there could be some modifications done on your original loom.
By the way, not sure this is the same for US model but the pinout diagram of the head unit should be on the bottom lid of the head unit itself.
Kaz

Kaz
It's likely head units in Japan are also failing.
Is there anyone there we could contact to see if someone has found a rebuilder or some other solution?

 

[Old Guy]

If it is just leaky electrolytic capacitors, it should be repairable. Electrolyte leaking on to the circuit board may require clean-up; but, normally does not result in permanent damage to the board. I would be surprised that Alpine would decline to repair it unless their repair skills no longer include the operation of a soldering iron! The repair could be time consuming and they may have judged that you might not be prepared to pay the cost of clean up and R&R of the capacitors. An option might be to find an electronics hobbyist and see if you can persuade them to replace the capacitors for you. Replacement capacitors are easy to source and failed capacitors are pretty obvious.

As a note, not all electrolytics will fail. Some time in the late eighties to early nineties a major or several major Asian capacitor manufacturers experimented with some different formulations for the electrolyte which didn't pan out in the long term. However, the problem didn't show up for several years. Early NSXs may have these capacitors in their electronics and may suffer from the accelerated failure rates. Late model NSXs may have capacitors with the revised formulations and may not suffer from the accelerated failure rates. As a secondary observation, electrolytics in general don't like heat. So an early model year car parked in a nice cool basement parking garage in Edmonton may still have an original head unit in operating condition. A late model NSX that always gets parked out in the sunshine in Phoenix may also suffer from early demise of its electronics.

 

[tof]

Thanks to all, especially Kaz and Old Guy, for the help and encouragement on this issue.I'm not surprised that Alpine didn't want to attempt a repair on a board with a lot of electrolytic damage to the main board. In researching this issue on the internet, it seems like Kaz is one of the few people who will attempt to clean up a badly damaged board. Plus I suppose Alpine Electronics America may not have the skills in house to take on the work, may not find it cost-effective, or may have simply decided they didn't want to do anything but a minor repair on such an old unit. I know William's Electronics has started passing on a lot of repairs...their web site lists the 1991 NSX radio as simply non-repairable. Also, I've heard that United Radio Services in Syracuse (THE authorized Alpine repair shop) has stopped taking in these head units.


GOOD NEWS: I got a call from Alpine customer service yesterday. While the tech who inspected my unit did not think they had any replacement units in inventory, the customer service rep informed me that they, in fact, to have (at least) one, which they are sending me. They just needed my verbal authorization, accepting the replacement. Not sure if this is a new unit or reconditioned but either way I am happy. No additional charge beyond the 250 I sent them for the repair.Also, I have to add that everyone I spoke with at Alpine was friendly, courteous, and professional. Even had they not been able to help me I would still have had a very positive impression of their customer service. If the story ends as happily as it seems it might, I will definitely post something here and on the Vendor Feedback forum.

 

[robbiedawg]

guys,forgive me if i missed something,but i was wondering why folks were trying to get alpine to fix the head units- i presume then that they were the original manufacturer of them? thanks

 

[JD Cross]

Finally heard back from the Canadian arm of Alpine (Gentec Ltd.).
They advise no parts available and units are unrepairable.
Looks like aftermarket for all of us with failing units.

 

[tof]

guys,forgive me if i missed something,but i was wondering why folks were trying to get alpine to fix the head units- i presume then that they were the original manufacturer of them? thanks

Yes, the speakers and their amps are Bose but the head unit is Alpine.

Finally heard back from the Canadian arm of Alpine (Gentec Ltd.).
They advise no parts available and units are unrepairable.
Looks like aftermarket for all of us with failing units.

Jim, before you give up, why not give Alpine in Torrence. You never know unless you ask.
I assume the US and Canadian units are identical. If they say no, maybe you could ship it to one of our US based primers and they could get it fixed for you. I would do it but they already have my name, address, phone, etc, and would probably question another repair so soon.

 

[Old Guy]

I would do it but they already have my name, address, phone, etc, and would probably question another repair so soon.

You could explain the recurring head unit repairs as being a manifestation of a serial obsessive multiple NSX ownership disorder. I am sure there must be an entry in the DSM-5 under which that could qualify as a psychiatric disorder of some kind.

 

[BB]

Finally heard back from the Canadian arm of Alpine (Gentec Ltd.).
They advise no parts available and units are unrepairable.
Looks like aftermarket for all of us with failing units.

There is another option....
39100-SL0-A04 TUNER ASSY. (AM/FM/CAS) (ALPINE) $2,212.50

Although I wonder when these units were last manufactured. Have these units been sitting in a warehouse for 20 years? The other option is to buy a used unit that still works. I see these appear on Japanese auction sites occasionally.