No sound in the car
No sound from the speakers after switching on the radio. The fault may be due to board damage caused by moisture or an overvoltage. We check the module and refurbish the main board.
No sound, a blown fuse, or a MOST communication fault? We repair the BMW Harman Kardon Logic7 amplifier used in BMW F10, F30 and F33, and in selected G11–G12 and G20 versions. Send us the removed module with a description of the symptoms, and we will check it in our workshop.

Written repair warranty
Quote for approval before repair
Courier shipping from anywhere in Poland
Quick repair quote
The BMW Harman Kardon Logic7 amplifier is a factory audio unit fitted in some BMWs. It is manufactured by Harman Becker. It is found in BMW F10, F30 and F33 models, and in selected G11–G12 and G20 versions, from around 2010 onwards (depending on the part number).
You can identify it by its distinctive casing with cooling fins. The amplifier is fitted in the boot and may be on the left side, in a dedicated compartment. Check the parts catalogue by VIN if you need the exact fitting location and part number.
When submitting the unit, describe exactly what is happening: no sound, a blown fuse, or a no communication message. Before sending it off, you can send a photo of the label with the part number. You send us the removed module only — we check it in our workshop.
The symptoms help describe the fault. We confirm the cause after checking the removed module.
No sound from the speakers after switching on the radio. The fault may be due to board damage caused by moisture or an overvoltage. We check the module and refurbish the main board.
The audio system fuse has blown and the sound does not work. This may indicate amplifier damage after a short circuit or contact with moisture. We check the cause and refurbish the power supply section and audio paths.
A MOST communication fault appears. Communication problems may result from board damage. After checking the module, we determine the scope of work and refurbish the damaged sections.
White or green deposits and signs of water damage may be visible on the circuit board. These may be signs of corrosion and short circuits. We check the condition of the board and rebuild the damaged components and tracks.
We check the removed module, its mechanical condition and signs of corrosion. After inspection, we confirm the scope of work and the price.
We refurbish the main board: the power supply section, communication and audio paths.
After the repair, we test the amplifier and send it back safely packed.
We refurbish your amplifier instead of replacing it with another unit. We confirm the scope of work and the price after checking the module, and we start the repair after your approval.
You do not need to bring the vehicle in. Describe the problem and we will help you work out what to remove and send. After inspection, you will receive a quote for approval — only then will we start work.
01
Write what is happening in the vehicle, state the make, model and year. Add a photo of the device, the error screen or the nameplate sticker, if you have one. On that basis, we will initially assess whether we can help.
02
Not sure whether to remove the radio, screen, amplifier or another unit? We will advise which component to check, how to prepare it for shipping and how to pack the parcel safely.
03
In the workshop we carry out diagnostics, confirm the source of the problem and define the scope of work. We send a quote for approval. We only start work after your approval.
04
We remove the cause of the fault, test the device and send it back safely packed for refitting. Every repair we carry out is covered by a warranty.
Answers to questions about the Logic7 amplifier. We identify the cause after checking the module.
No sound may be caused by an amplifier flood or a voltage surge when jump-starting the car with a booster. After checking the module, we confirm the cause and refurbish the main board.
A blown fuse may indicate a short circuit or damage resulting from contact with moisture. We check the amplifier and repair the power supply section, and remove the effects of the short circuit.
Drying alone may not be enough if there has been corrosion or damage to electronic components. We check the module and rebuild damaged tracks and components.
No. If you decide not to proceed, or the unit cannot be repaired or the fault lies outside the module, diagnosis and return shipping are free of charge.
Water in the boot and a blown 40A fuse are a common cause of silence in the radio. Find out when repair makes sense — free diagnostics and a quote within 24h.