Radio or amplifier issues

[m60power]

Two of the front speakers in my 9/93 build date e32 stopped working and I believe it's a problem with the amplifier in the trunk. Yesterday when playing music on a drive there were sharp crackling / popping sounds intermittently coming from the front right dash speaker (I think). This wasn't the typical crackling or static that can occur when adjusting the radio volume knob; it occurred randomly with the volume at a set level.

When I drove the car again this morning the crackling was gone however it sounded like the right side channel was quiet or gone. Setting the radio fade and balance to each corner of the car I found that the right front dash speaker and kick panel speaker weren't playing, but the right front tweeter still worked. The right rear speaker and tweeter work too. As far as I know the radio outputs 4 channels (one for each corner of the car) to the rear amplifier, which then divides each channel into separate outputs (10 in total) to the individual speakers at each corner of the car via its internal crossovers... I'm guessing my issue is the with the amplifier itself because only 2 of the 3 front right speakers are out rather than the entire front right channel. If the radio was the problem then I don't think the front right tweeter would work either because that entire channel (all 3 speakers on front right) would be out?

I think I remember reading there were 3 versions of amplifiers in the e34/e32, but I'm not sure of the cut-off dates of production, and I'm having trouble finding pictures of each variant. I think my amplifier would be the 2nd of the 3 versions, which should have 4 channels of amplification (one for each corner) feeding a 10-channel passive crossover for output to each of the 10 individual speakers. So maybe the capacitors or something in the amp are going bad? I think the late production (maybe '95 model year?) had a much different 10 channel active amplifier setup, correct?

Are there any companies or whatnot the rebuild these old amplifiers? I don't have the knowledge or desire to try and build an aftermarket amplifier / crossover system for the 10 speaker system...

[m60power]

Pulled the amp out for a closer look

20220918_175102.jpg

It's part number 65128375007

20220918_180007.jpg 20220918_175954.jpg

Not sure if it's the latest variant of the e32/e34 amps, but the internals are definitely the active crossovers, 10-channels of amplification, rather than a passive crossover setup. I didn't see any obvious signs of burnt or damaged components on the boards but I'm not an electronics expert...

EDIT: Looking at photos of late model amplifiers (95 model year) and earlier model amplifiers (like 92 - 93), it appears mine has the casing and heat sink design of the amps that have the passive crossover board, but the internals of my amp are much different; there's no array of coils and capacitors or whatnot like I see in pictures from those who bypassed the factory amp and used the stock passive crossover board... And the casing and heat sink design of the late production active crossover amps (that I could find photos of) look different than my amplifier. Not sure what that's about. Maybe it could be differences between E32 and E34 amps??

[m60power]

According to the realoem ETK, part number 65128361781 is the current version of the e32 amplifier, however, the part number of my amp (65128375007) was only produced for less than a year and it's stated to be nonexchangeable with the other variants:

e32 amp pn.JPG

I guess that could make it a bit difficult if I need to find a replacement. I wonder what's unique about my amp's part number? Maybe the wire harness connectors or something more substantial like passive vs. active crossovers for the internal design?

[shogun]

Maybe you find a radio repair shop which can repair it. Not the same, but years ago one of my wrenching buddies repaired his unit and changed 6 capacitors http://infinitier.ddo.jp/e32/page/ma...inte_50529.htm
google translated text from Japanese to English: Hi-Fi amplifier repair part 1
Take-'s highline is equipped with a hi-fi amplifier. Well, even if it is not a highline, it is installed according to each car model.The audio system of the late 750 has a 10-speaker configuration with 6 front speakers and 4 rear speakers. This is also due to differences in speaker configuration and amplifier configuration depending on the time. It has nothing to do with audio, but as you can see, the trunk lid stay, that is, the side of the rear seat, is not only a stay but also a reinforcing plate stretched vertically and horizontally. Domestic cars only have a tire house at most, but the E32 is strongly reinforced from the tire house to the C pillar.
Why? It's just for passenger protection. The rear seat area of ​​the 7 Series, where the VIP rides, is protected by a tough shell, which is thoroughly hidden. .
This is a Hi-Fi amplifier. There is a similar model for the 5 series, and the audio manufacturer in charge differs depending on the country of manufacture.　
The important amplifier is hidden on the left side of the rear trunk. Although it is a fairly large trunk, it is for this reason that it does not take the full capacity on the left and right.
You can see the Made in Japan and BMW original logos. By the way, Made in Germany was stamped on the image received from the owner in Germany. BMW is not an audio manufacturer, so naturally it is an OEM. This is made by that Alpine. Shoot of the serial number without any meaning .In front of the stay, you can see the connectors that connect to the CD changer, etc.
Even similar models have different connectors depending on the configuration. The left side is the power supply and input signal system, so it is almost the same, but the right side connector has a different number of pins depending on the number of speakers configured. If you look at the connector on the left, you can see that it's a power supply, ground, and input system.The rest of the input system is turned over. Well, if you think about it, you can see that there are 8 wires on the front left and right and rear left and right, 2 power wires and 2 ground wires.I will omit which one for now. I will explain it when I change to the multi-amplifier configuration next time. This is the output connector. This is also expected. It's a composition of 10 bundles of 20, but it's twisted properly.Well, as the title says, this time the purpose is repair.
In the first place, what is wrong with this amplifier is that the output balance from each speaker is different depending on the day (explosion). Well, it's common for old amps to last about 10 years if they aren't maintained. Take is a geek who is picky about audio at home, but the car was in a good condition and left to play. As you can see, it's made of alpine, so it's normal.10 speakers are driven by 6 capacitors, don't get me wrong, the rear tweeter and full range have only one drive power supply and are completely independent on the network. (Not for those who aren't interested). As promised, the power supply has become unstable due to the leakage of the capacitor. So I replaced 6 drive capacitors that were leaking. Actually, I wanted a gold capacitor or a black capacitor when I replaced it, but since there is a possibility that there may be other problems after repairing it in the first place, I decided to replace it with a cheaper one and see how it goes.Image after replacement. When I put the amp back in and checked, the balance system was completely cured. The right rear circuit is probably dead...But as for the sound. . . Well, it's not aged, so it's a very light sound, and the power supply is the life of the amp.

[m60power]

Awesome! Thanks for that info and webpage link, shogun! That amplifier he repaired is the same model and part number as mine so I'll try my hand at replacing the capacitors to see if that fixes it. In the meantime I bought a used amp off Ebay, swapped it into the car, and it fixed the speaker issues. So the problem is definitely in my amplifier.

[Jimbatt1]

So, stereo works when it wants to upon starting. I have tried a new amp and a loaner head unit. Does not matter old and new work the same. If the car starts and sound comes on it will stay on for as long as the car is running. Them ovement of the car makes no difference so nothing is loose. Onc parked the stereo may have worked perfectly for three hours. Turn car off for five minutes restart and no sound. Guess to the dealer I go?. Ideas?

[shogun]

@ Jimbatt1, your 2017 430i x drive coupe is a compl. different system set up from our + 30 year old E32 series. Ask here in the Car Audio Electronics forum https://www.bimmerforums.com/forum/f...ed-by-Bavsound

[m60power]

Well that used amp got a little over a year of trouble-free use but now it is failing... I'm losing speakers again along with the crackling sound coming from the two speakers that are dropping out. Looks like I'll have to actually start fixing these damn things because the internal electronics seem to be getting to the age where the failure rates are increasing.