75ZT Community

Anyone had this done?
Looks good if you need a repair anyway
http://forums.m3cutters.co.uk/showthread.php?t=48861
More info here
http://www.fullfatrr.com/forum/topic10342.html

I've been trying to figure out exactly how to do it as a service to other owners on here. So far the dead BM54s have been either ver very dead, or not shown any faults in a quick test. My own BM54 has a minor noise that you only hear with the sound turned down, so I'm leaving it alone until it gets worse.

With most radios, you just resolder some joints, or at worst replace a chip. BM54 has a weird amp chip which can't be repaired or replaced. There's a few places that do repairs / upgrades and also you can buy repirs kits. However you need to be careful of a couple of things:

1. You need to be quite skilled to fit the kit as some of the soldering and track cutting needs to be done carefully.
2. If you are using a later BM54 and want to use either the aux in feature, or the phone input, then you have to ask the seller if their repair / upgrade / kit supporst this as some don't.

Hi guys, i am the guy the links are referring to. If any of you any questions, please just ask away.

I shall give a quick guideline to the BM54 unit, and what I can do to these units.

Lets start with faults:

-Channel failure, 1 or more speakers stop working. This is the most common, and my favourite repair to do, as this not only fixes the fault, but also improves the sound quality.
-Buzzing noises, which can vary, but eventually they get worse and sound like an old computer beep. Originally starts with either change of volume, bass or treble. Sometimes, at low volume the buzzing noise comes out of all speakers, and sometimes when the volume is increased. Same with the bass and treble. I also repair this fault.

Just a note, regarding re-soldering dry joints on these units. This doesn't fix any of the above problems, this is mainly on the BM24 units.

Upgrades:

-Amp upgrades, as above, this is done when you have a channel failure. Completely different to the buzz noise fault.

-Firmware upgrade. All BM54 units can be upgraded by me. This will enable 3 mains things:
Aux in
MP3 6 disc changer iD3 tags
TMC Dynamic Routing

-RCA Preouts, for amp and sub install. A remote cable is also installed, to make the install easier. This one is widely available on the internet, with pictures etc. However, the amount of people that have bought me their unit after they tried this, was not gentle enough, and de-soldered the tiny capacitors off!

-Aux in via 3.5mm jack

-Iphone/Ipod cable which charges and plays music via AUX.

-Bluetooth media stream.


Cheers!

Baris

Thanks for offering your expertise to the members here. Most welcome.

Hi Baris. My understanding is the channel failures are down to the non replaceable amp chips that are fixed to the board. The failure seems very similar to one I've come across on laptops and computer graphics cards where a thing called a ball grid array (BGA) is used to fix the chip to the PCB (Printed Circuit Board) instead of pins. Heat and PCB flexing cause the BGA to fail and the graphics card or laptop is effectively useless. However a simple rework is effective: 10 minutes at 190C. Because the failure starts slowly and becomes worse, I don't think it can be the chips themselves that fail

Now I know your upgrade gives better sound, but do you know if anyone has tried the reflow on the chips?

Finally, I read that on some versions, particularly BM54 back (the round pin version) the chip that allows phone input and aux input is missing and has to be added. Have I misunderstood this, or was that just wrong.

Hi Baris

Nice job!!!

This means .....please stay with a BM24 far more reliable

Hi Baris. My understanding is the channel failures are down to the non replaceable amp chips that are fixed to the board.

Correct.

The failure seems very similar to one I've come across on laptops and computer graphics cards where a thing called a ball grid array (BGA) is used to fix the chip to the PCB instead of pins. Heat and PCB flexing cause the BGA to fail and the graphics card or laptop is effectively useless. However a simple rework is effective: 10 minutes at 190C. Because the failure starts slowly and becomes worse, I don't think it can be the chips themselves that fail

With the BM54s case, it is.

Now I know your upgrade gives better sound, but do you know if anyone has tried the reflow on the chips?

Nope. They usually fail on X5s the most, so could be down to the heat, as they are located deep under the spare wheel.

Finally, I read that on some versions, particularly BM54 back (the round pin version) the chip that allows phone input and aux input is missing and has to be added. Have I misunderstood this, or was that just wrong.

Both flat and round pins have telephone and AUX input. Some of the older flat pins will require a firmware upgrade to work the AUX in.

Thanks for the reply. Excellent news for those with the older units!

Having had the Upgrade done on my BM54 by Baris, I can vouch for his services, I posted the unit on a Tuesday, I had it back by Thursday Lunchtime! Fixed my front speaker faults, and upgraded the firmware!

x10rich wrote:Having had the Upgrade done on my BM54 by Baris, I can vouch for his services, I posted the unit on a Tuesday, I had it back by Thursday Lunchtime! Fixed my front speaker faults, and upgraded the firmware!

Thanks for the update, it's always good to get good feedback on traders.

Yep, his firmware upgrade allows MP3 ID Tag support (if you have the later autochanger) and Dynamic Routing (via TMC) (and a couple of other things I have forgotten) Well worth it

Hi Baris, I have the round pin BM54 can you do your firmware upgrade to it, I would like to get the MP3 id tags in particular.

Geoff130 wrote:Hi Baris, I have the round pin BM54 can you do your firmware upgrade to it, I would like to get the MP3 id tags in particular.

Baris doesn't spend much time on this forum, I suggest you either PM or email him.
member/Baris/

You can make contact with him here

http://www.carphonics.co.uk/Contact.htm

Thanks, I have emailed him.

Hello guys,

Here are detailed instructions for repairing your Becker BM54 audio module (loosing sound problem), hope it will be useful:

https://www.youtube.com/watch?v=gCdkXn0aT_o