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Can a failed BM54 amp take out the whole audio system?

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Thanks for all your help guys, but in the interests of narrowing the problem down a bit more, I noticed when i jumped in the car today that the DSP option was gone from the screen right after turning the key, and came back a split second later, so I take this to mean something sound wise is responding to polls albeit briefly?

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Well, if it's what Baris suggests, the radio not providing enough voltage to turn on the DSP amp, then it's possible that it's marginal. Sometimes just enough, sometimes just not enough. Do you have a multimeter that you could use to measure the output of pin 13 from the radio?

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Pin 13 is the wire coming out next to where the fuse is on the bm54. I think it's white and yellow cable.

Sometimes, it might produce 12v, even though the bm54 is not powering on, but it's rare.

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Sorry for the potentially stupid question, but I'm assuming power comes into the BM54 via the same plug that pin 13 is in, and so I'm assuming I'll need to yank that wire out of the plug to get a voltmeter in-between? or is there an easier way to do it?

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No, pin 16 is ignition and pin 15 is live. Pin 13 is 12v coming out of the bm54. You can put the ground connection on your multimeter in one of the holes on the bm54, as it sits nicely in there, and use the other connection from behind the bm54 plug, whilst the unit is plugged in. Just slowly push it in there, without any force.

If I'm right, you should have no voltage in pin 13.

Edited by XKaLiBaR

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Ah right cheers, I didn't see that the connections were as wide as that. Voltage was hovering about 11.46-11.47v, so I think we've found our troublemaker?

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You did say the left side of the screen is off, including the orange light, because your first post mentions, you not being able to change modes.

The voltage reading is fine.

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Sorry I'm not sure i follow, 11.5v is fine voltage wise, but is my BM54 still the culprit? I just want to make sure I know where the issue is before I spend cash getting it fixed

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As I said early in the thread, there are some odd characteristics here :

1) Radio won't turn on or allow source selection.

2) DSP greys out on the monitor.

3) Intravee/KCA-420i does not display Alpine logo or charge.

Any one in isolation I could explain, but all three being intermittent is rather strange and IMO can not be explained by a faulty radio alone or a faulty DSP amp alone.

The fact that the DSP amp is not responding to polls from the Nav or Radio indicates either that the amp is faulty, not powered or that there is a fault in the iBus to the amp. As you can see the messages to the amp there is not a total iBus failure.

Lack of the ability to turn on the radio points to a faulty radio, bad connection or iBus fault.

The KCA-420i not charging the iPod or displaying the logo indicates no power on the CD Changer connection or iBus communication fault.

Ability to control the Nav when the radio can not be selected indicates that the monitor and Nav both have power and iBus.

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Well i jumped in my car leaving work today and everything was working fine! I didn't do anything to it, so I expect it to pack up again at some point, but my iPhone worked, radio was there. Didn't try the speech from the nav but i assume that will be working too

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Dead again! Worked for about 10 seconds tonight, until I foolishly clicked the volume knob in to play a song on my iPhone, at which point it all died again. My iPhone continued to say it could not be charged though, so progress on that front?

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The iPhone needs a charge converter, unless it's the original version. If it's detecting that it's connected the the KCA-420i/Intravee is powering up corectly. If you have a charge converter it may be faulty or the KCA-420i cable may be faulty, or the dock cnnector on the iPhone may be faulty!

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Just as an update to anyone who ever gets this problem, however unlikely that might be, I ended up sending my BM54 to Baris for repairs. He had a look at it and said it was actually fine, which made my heart sink a bit, but he had resoldered everything for free since it was never broke in the first place. Was resigned to chasing a replacement DSP amp or planning out aftermarket solution when the BM54 arrived back. I promptly went to plug it in only to get a huge arc of electricity go from the plug to the BM54 as I got the plug near it. Was expecting the entire thing to be f**ked after that, but everything has been working perfectly ever since, although given the whole electrics of my car have dropped out once or twice since then I'm still not totally in the clear, but atleast my audio issues are solved!

 

Also since I updated the Intravee way back when I first started trying to figure this out with everyone's help here, and now i can actually use, I'm having great fun with all the extra features it has now! Worth the money for the auto folding mirrors alone :D

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Very interesting topic. I wondered if any of you guys could figure out what my radio sat nav was playing at.

I had an EXTRONS head unit fitted to my 2005 X5 e53.

Fitted new wiring harness from head unit to boot,removed stock cd, sat nav and tv module as the new Extrons is an Android unit Plugged it into the BM54 amp and it worked fine for a few days then stopped audio?. everything works as it should but just no sound??.

I sent the audio module down to Revtronics in Bradford who repaired and up graded it,plugged it back in and sound/audio worked perfectly for a few days but has lost sound again??. Its becoming a bit frustrating now!.

Would really appreciate some advise on what the problem could be.

Cheers guys

 

 

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1 hour ago, Ian B said:

Very interesting topic. I wondered if any of you guys could figure out what my radio sat nav was playing at.

I had an EXTRONS head unit fitted to my 2005 X5 e53.

Fitted new wiring harness from head unit to boot,removed stock cd, sat nav and tv module as the new Extrons is an Android unit Plugged it into the BM54 amp and it worked fine for a few days then stopped audio?. everything works as it should but just no sound??.

I sent the audio module down to Revtronics in Bradford who repaired and up graded it,plugged it back in and sound/audio worked perfectly for a few days but has lost sound again??. Its becoming a bit frustrating now!.

Would really appreciate some advise on what the problem could be.

Cheers guys

 

 

You sent your unit to revtronic, that's where the problem is. The amount of there work I've had to re do and cartronics. 

 

A warning to all about cartronics, these guys are con artists. Charged a customer last week £300 for testing the fault and not being able to repair it. £300 and didn't fix anything. I diagnosed the fault over the phone and repaired within half an hour of him popping over and only cost him £99.99. 

 

Same again a week earlier, they tried to sell a customer a bm54 for £400, after taking £200 for testing and saying they can't repair his unit. 

 

I repaired it in half an hour. The unit had previously been repaired by sound secure, and their kit had failed and cartronics couldn't manage to remove it, didn't even attempt to remove it. Just wanted to sell a unit for £400, exchange for his perfectly repairable unit. 

 

My knowlegde is free, give me a ring. Stop giving money to these scum bags. 

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This is the most informative thread I have on this issue I have encountered. Sadly , judging by the dates of the conversions both of these cars have been retired by now. I am hoping someone with as much knowledge can respond.

I inherited an e39 with a similar problem. 

I do not have all the diagnostic tools available to me that those with the m5 above do. However, I  have access to a great many replacement components.

I manage to get the entire system working with the exception of audio to the left rear speakers.

I can get the Radio, cassette, CD player working - I have no NAV.

But - the entire system loses sound in exactly 40 seconds from the system being powered on.

This happens no matter what sub component is delivering the audio signal.

It cuts out in 40 seconds - not 39 and not 41 but a consistent 40 seconds.

Everything stays lit and powered but the sound disappears; the display shows the settings, the CD continues to play the CD , radio sends signal from the radio station, tape in cassette player keeps winding forward.

If I power off the DSP (Display) unit and power it on again. Power cuts to the sub components; then once powered on - resumes playing once re-selected through the DSP.

The sound returns for another 40 seconds. (Sound everywhere but left rear)

Reading this thread the issue appears to be Polling. Clues highlighted in orange.

 

RichardP

wrote in one of his responses:

"Posted January 26, 2013

There are no messages from the DSP amp in that log, which indicates that it's the probable cause.

Both the radio and the Nav should poll the DSP amp for it's status at regular intervals, the Nav (or Graphics driver to be more accurate) every 50 seconds, the radio every 20 seconds. Both of the poll messages are in your log, for example

from the Nav

IBUS: 00:12:02.86 3B 03 6A 01 53 [53]

from the radio

IBUS: 00:12:21.19 68 03 6A 01 00 [00]

The DSP amp should respond to both with

6A 04 FF 02 00 93

but this never appears in your log.

So, I think the DSP amp is faulty and not responding correctly."

 

There is also an entry that states that the older amplifiers "power Up without being polled".

XKaLiBaR

"Posted January 27, 2013

The fact that he has no orange light and control over the left side, indicates the bm54 is not powering up. If the bm54 is not powering up, then the DSP is not powering up, because the 12v remote from the bm54 that goes to the DSP, won't be producing any power.

The ibus signals in this case are irrelevant, trust me. Don't forget, the bm54 is still getting 12v sent into it, and the ibus signal. So parts of it might be working to send the signal you are referring to, but it's not switching on properly.

If it is an old bm54, I have more chance of bringing it back to life, than the newer units.

Just thought of another reason why you might be getting ibus signal, the older units seem to come on without sending an ibus signal. Hard to explain, but that could explain that."

 

My question is. Can anyone explain a 40 second interval?RichardP identified the NAV at 50, and radio at 20 - why 40? Is the first poll from the radio a given? So it shuts it down at 40?

Is it a delayed response from the polling before it shuts off?

Perhaps the CD Changer?

Can anyone explain? And - is there a fix?

 

Thinking it was an analog vs. Digital issue; I have swapped in over 20 different Head units . - with and without cassettes - they all lose sound in 40 seconds.

I have swapped in several amps with the same connections and they all fail for different reasons - plays right side only, sound has an echo or is muddy or does not work at all.

It is the original amp that works best but has this persistent issue. loses sound after 40 seconds.

Can it be fixed?

Other threads have pointed to a seating (Connection) issue - any thoughts appreciated.

Does anyone know which wire to the amp is responsible for sending / receiving the polling signal? Is it just the power wire?

Any help in solving this puzzle is appreciated.

 

 

 

 

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Your bm54 is at fault. The left side amps have failed. Perfectly repairable and it will sound better afterwards. You can send me the bm54, or pop down. I will test it on my bench before starting the repairs. 

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I work at a wrecking yard. I tried 20 different bm54 cassette/amps plus one out of an e53 with no cassette - They all had the same problem. Sound dropped after 40 seconds. I cannot believe all the bm54 I tried have the exact same problem.

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