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Discussion Starter #1 (Edited)
My sound system is cutting out periodically, especially if the car is moving. I think I have the problem narrowed down to the power wiring entering the amp. The amp has a heavy gauge brown wire (ground) and the small guage white wire (remote turn on signal) coming from the wire harness, through a two pole connector, then two a taped up component which I think is a capacitor or RC filter of some sort. The brown and white wire then proceed to the large connector on the DSP. When I tap this component, I can get the system to turn off, but then in a few seconds it turns on again.

This part has a BMW parts tag on it with pn 65 1 04 116 297. I searched the ETK and cannot find this part on any car, particularly the E39. I thought it was the RC filter listed with the DSP amps, but the part numbers don't match. Can anyone tell me what this is? I am hesitant just to cut it out if it is an RF filter of some sort (or maybe a relay that cuts the ground when the remote turn on is off)?

Update: I did a parts search on realoem and could not find the part. But When I put it into Pelicanparts search engine, it came back with one hit calling it an RC filter. I guess I unwrap the tape and take a look. Maybe upgrade to one of the more recent part numbers.
 

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i have the same problem, sound just cuts out for a few seconds then comes back up. I actually think it's the amp itself. can you post some pictures? i'm not 100% sure but i think it nothing to do with car moving, as mine does it even when car is stationary
 

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Post a pic - your ground should be going straight to the amplifier with nothing in the middle.

And you should not have a capacitor or filter at all.

d-
 

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Discussion Starter #4
i have the same problem, sound just cuts out for a few seconds then comes back up. I actually think it's the amp itself. can you post some pictures? i'm not 100% sure but i think it nothing to do with car moving, as mine does it even when car is stationary
Mine will also do it when stationary, depending on the position of the power feed cable with this RC filter. If you "jiggle" the wire or tap that filter, I can get the system go come on and off. I think there is a small turn on delay when power is restored to the white wire, which is why the system seem to come back after a short time period.
 

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Discussion Starter #5 (Edited)
Post a pic - your ground should be going straight to the amplifier with nothing in the middle.

And you should not have a capacitor or filter at all.

d-
Doug:

I confirmed with a dealership this morning that the part is an RC filter. It does not match the RC filters listed in the ETK for the 02 M5 with DSP. In fact, the dealer could not find the part listed in the ETK at all for any application, but it was still a valid part number and he could get the part.

Photos are posted below. One is of the two pin connector that splices in the filter. The other is of the filter itself (297). The white wire and brown wire come from the wire harness, through the two pin connector, through the RC filter, then to the 15 pin connector on the DSP amp.

Why do you say there should be no filter? The ETK does list an RC filter for DSP for cars with NAV after about 2002.
 

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I originally said you shouldn't have one because I don't have one in my car (before or after DSP removal).

As I think about it, however, I guess I can see where, in a car with this many electronic devices, you might need a low pass filter (which is what an RC filter is) to prevent any noise from entering via the power lines.

It would clearly be optional and only needed in cars w/ noise.

In case you are curious, an RC filter is nothing more than a capacitor and a resistor in parallel (for current filtering) or series (for voltage filtering). It shouldn't be a very expensive part to replace for our cars since they don't draw much current.

I must say that I am intrigued that they have it on the power (white) and ground (brown) simultaneously. I can only imagine it must be 2 separate filters combined in one housing...

Doug
 

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Discussion Starter #7
I originally said you shouldn't have one because I don't have one in my car (before or after DSP removal).

As I think about it, however, I guess I can see where, in a car with this many electronic devices, you might need a low pass filter (which is what an RC filter is) to prevent any noise from entering via the power lines.

It would clearly be optional and only needed in cars w/ noise.

In case you are curious, an RC filter is nothing more than a capacitor and a resistor in parallel (for current filtering) or series (for voltage filtering). It shouldn't be a very expensive part to replace for our cars since they don't draw much current.

I must say that I am intrigued that they have it on the power (white) and ground (brown) simultaneously. I can only imagine it must be 2 separate filters combined in one housing...

Doug
Doug:
Actually makes perfect sense to me. They are filtering the signal line (white remote turn on signal) relative to ground. The brown wire is the ground reference, and the filter is connected between the white wire and ground or the brown wire. To filter both (relative to the chassis), they would need a third wire from the filter to the chassis (there is none). Probably a bad connection were the white wire is passed through the filter that is causing the intermittent connection.
 

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Discussion Starter #9
DONK - uh yeah, I guess you would have to have a ground reference in there, wouldn't you?

d-
Yup.
Sounds like, based on your comments, you removed your DSP amp for - the non DSP or an aftermarket amp?
I was looking back through the archives and found a pretty detailed description of the DSP back in 1996 -99. BMW was using these Phillips TDA1560Q output IC power amps in the DSP as the channel power outputs. I was curious because these chips are still available, and I may be able to repair my DSP blown channels by replacing the ICs. They are very unique in that they use a single ended 12-14V power supply, whereas most power amp audio ICs need 18 to 24V dual (+/-) supplies which require DC/DC converters. The down side is they have a considerable amount of distortion with power levels as low as 30W, which I am sure impacts the sound quality.
 

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agree with Douglas and can confirm that mine has not got LP filter. in fact mine has not got dsp module either :(
 

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Discussion Starter #11
agree with Douglas and can confirm that mine has not got LP filter. in fact mine has not got dsp module either :(
You probably do have a remote turn on signal line for the non-DSP amp. I would check the connection where this signal line enters the connector on the amp. Perhaps the pins are loose or are oxidized.
 

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You probably do have a remote turn on signal line for the non-DSP amp. I would check the connection where this signal line enters the connector on the amp. Perhaps the pins are loose or are oxidized.
that's what i though initially so i did everything i could to make sure it's making a proper connection but no luck. it got better, before when it used to cut out until i wiggled the main quad connector it would not come back, now it does every time but still not 100% :S i'm thinking of buying another unit to eliminate amp out of this equation.
 

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Discussion Starter #13
that's what i though initially so i did everything i could to make sure it's making a proper connection but no luck. it got better, before when it used to cut out until i wiggled the main quad connector it would not come back, now it does every time but still not 100% :S i'm thinking of buying another unit to eliminate amp out of this equation.
Before you do that you might want to consider cleaning and treating the contacts in both the mating connectors. If its a problem in the wire side of the connector, buying a new amp won't solve the problem. I use a product called DeoxIT. It should be available in a good electronics supply house. They have two compounds, the D100L (red liquid) for cleaning and rejuvinating contacts; and the G100L (gold liquid) for conditioning and protecting after cleaning. The other thing to check is be sure the pins are fully seated in the housing. They have little barbs on them that snap into the plastic housing. If they are not fully seated, making up the connector pushes out the pins and you get intermittent contact. My problem may also be connector related, but I won't know until I replace that filter.
 

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I went aftermarket - no reason to install another underpowered amp :)

As for the rest of your post: uh, ok :) Seriously, you are correct about the distortion and I'll take your word for the voltage requirements. If you want information from "the man", this would be a good read - shouldn't take more than an hour or two!

d-
 

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Discussion Starter #15
I went aftermarket - no reason to install another underpowered amp :)

As for the rest of your post: uh, ok :) Seriously, you are correct about the distortion and I'll take your word for the voltage requirements. If you want information from "the man", this would be a good read - shouldn't take more than an hour or two!

d-
Thanks. I found that thread when I was doing my searches on the DSP. The voltage requirements were obtained off the spec sheet for the Phillips amp. But I still need to confirm BMW has that amp in my DSP.
I am considering building my own 6 channel amp that will be mounted in the same location as the current DSP, and will be a "buffer" driver between the DSP output and the speakers. Yes, I read the concerns expressed a while back about the quality of sound coming from the DSP, but those amps are not bad if they drive high impedance loads at low power levels. I have not been able to find a really compact commercial 6 channel amp that I can mount near the current DSP. I will drive the front six speakers with the buffer amp, and use the current DSP for the rear four speakers sans the subwoofers. A conventional aftermarket mono amp for the subwoofers will probably be used to take more load off the DSP, and supply a lot more power to the drivers.
 

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Have you checked the white line with a multi-meter? If it has power then the issue is the amp - I wouldn't replace the amp until I'd checked the line first...

d-
 

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Discussion Starter #17
Have you checked the white line with a multi-meter? If it has power then the issue is the amp - I wouldn't replace the amp until I'd checked the line first...

d-
I took everthing apart this afternoon. I found that the female contact coupled to large gage brown wire was not inserted properly into the connector at the DSP. I re-inserted it with needle nose and it snapped in place as it should. This was probably the cause of the intermittent power connection. I will finish installing the tweeters and see if the two right high freq channels are still dead. When everything was apart, I had a chance to confirm that BMW is still using the Phillips amps in the DSP as previously described. So I can probably replace the specific amps for any blown channel without too much hassle.
 

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I took everthing apart this afternoon. I found that the female contact coupled to large gage brown wire was not inserted properly into the connector at the DSP. I re-inserted it with needle nose and it snapped in place as it should. This was probably the cause of the intermittent power connection. I will finish installing the tweeters and see if the two right high freq channels are still dead. When everything was apart, I had a chance to confirm that BMW is still using the Phillips amps in the DSP as previously described. So I can probably replace the specific amps for any blown channel without too much hassle.
It is always nice when the problem is something simple.

In my experience with amps I haven't typically found the opamp to be the part that blows - usually it is a shorted out transistor. Nevertheless, since you are handy in there, I doubt it will matter which component it is! Lastly, there was a writeup from a gent over on Bimmerfest (I think) who took his apart and increased the cap size for the subs to double the output. I mention this only because if you are replacing components and know your way around, you may want to do so...

d-
 

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Discussion Starter #19
It is always nice when the problem is something simple.

In my experience with amps I haven't typically found the opamp to be the part that blows - usually it is a shorted out transistor. Nevertheless, since you are handy in there, I doubt it will matter which component it is! Lastly, there was a writeup from a gent over on Bimmerfest (I think) who took his apart and increased the cap size for the subs to double the output. I mention this only because if you are replacing components and know your way around, you may want to do so...

d-
Doug:
You are usually correct when there are discrete power transistors. But in this case, the power output stages are part of these IC power op amps. In other words, they drive the speaker loads directly. I spoke with one of the head Techs at BSW last week, and he told me these little power amp ICs are pretty rugged. He has never blown a channel in all the years he has been installing replacement speakers. They are supposed to be short circuit proof, so perhaps they went into a protection mode when I was working with them. I did notice an array of large caps mounted in the center of one of the boards. I think these are the caps that are used by the power amps to create the minus power supply rail. The chip creates a minus power supply sorce by charging up the capacitor, then switching its leads to connect the + side to ground, and the minus side powers the - rail. So increasing the capacitance probably reduces ripple on the minus rail while the charge is being drained during negative signals in the music. Just how large you can make these capacitors may be limited to what will burn out when they are being charged. I need to check the spec sheet. The biggest pain I face if the amps are blown is determining which of the 11 or 12 is bad, since tracing the proper wire colors from the pc board through to the speakers is not easy.
 

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Doug:
You are usually correct when there are discrete power transistors. But in this case, the power output stages are part of these IC power op amps. In other words, they drive the speaker loads directly. I spoke with one of the head Techs at BSW last week, and he told me these little power amp ICs are pretty rugged. He has never blown a channel in all the years he has been installing replacement speakers. They are supposed to be short circuit proof, so perhaps they went into a protection mode when I was working with them. I did notice an array of large caps mounted in the center of one of the boards. I think these are the caps that are used by the power amps to create the minus power supply rail. The chip creates a minus power supply sorce by charging up the capacitor, then switching its leads to connect the + side to ground, and the minus side powers the - rail. So increasing the capacitance probably reduces ripple on the minus rail while the charge is being drained during negative signals in the music. Just how large you can make these capacitors may be limited to what will burn out when they are being charged. I need to check the spec sheet. The biggest pain I face if the amps are blown is determining which of the 11 or 12 is bad, since tracing the proper wire colors from the pc board through to the speakers is not easy.
I just learned something new today :)

Thanks!

Doug
 
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