Contact Carphonics, they know exactly what the fault is with yours and can repair within half hour if you popped down to them. If you go to cartronics they will take £400 off you for testing and say it's not repairable lol

Why did you downgrade and have to buy an extra loom for downgrading????

You cannot upgrade the bm54 back. You will lose the navigation sound. If you read few posts up, you will see I already pointed this out.

yep. I' read all the posts here.
bought it beckause didnt know that the trick wouldnt work. i bougt it knew for the price lower than used ones is sold in my country.
i dont need navi voice. really for me it is little bit annoying, so i prefer listen to the music.
so my purpose of upgrading bm54 back is to get aux and bluetooth phone. and also i have MD in head and bm54 back recognises it as a tape and doesnt play. not i big deal but if functionality will resurrect after uprade it would be good too.
so in my case upgrade shoud do the trick? aux i understand yes. but about phone no info found.

The MD and Auxilairy might work. I've done the upgrade twice on the back units, and once the auxilairy worked and on another unit it didn't work.

You know we sell fully loaded bm54 units for around £320. That's stage 2 amp upgrade, latest firmware, Bluetooth auxiliary input and rca preouts.

Good info!
Maybe different units ? Mine is 2005 year made. And the model is just in first post.
Ive bout my back for 94 pound for new unit. 320 is quite expensife for me because of currency conversation.
I ve just wonder if there is different firmware for unit for like x5 with dsp and for unit for e46 with HK?

All Bm54's are compatible with HK and DSP. Its all built into the firmware.

How bad is your original bm54? Just power out? Did you try and resolder the cracked solder joints? Sometimes that can be a cause, for no power.

Great thank for info!!

My original BM is already repaired with amp change. Becker amps deleted. Althow deleted some condersors and on its plase doldered wires for amp in's.
It was fine for the first, but it become shutting off. I opened and saw that + is in the air. So i soldered it. Next one channel stoped working , i soldered. And than one channell started scrapping and make loud scretch nouse. That was last point and i decided to change it. And found a man in another city selling BM back and he that aux and bt should work like mine.
And after i purchased his phone number became inactive.
I sutisfied with sound quality withbm back but want aux. i have mine aux bluetooth converter, so want to play music this way.

If it's still powering up, it's repairable. You should send it to Carphonics, as repairs aren't that expensive, unless you've chopped the wiring already. :(

it's powering up. more of it it's working)) exept one channel(i dissassabled the wires for creaking channel)
but my main pcb is missing some condensors(was destroyed when the unit was repaired).
and right now when i call someone with BT connected - people hear me, but i cant hear anyone - no sound in a car.
i would like to know - if i make a photos and send them to you could you analize them and approove or disprove if you could resatore the condensors for the BT to work?

We have a lot of spare boards, so shouldn't be a problem to replace. Send the photos over, email below.
As always with us, no charge if it's not repairable.