Mercedes COMAND NTG2: the screen and steering wheel controls work, but the radio buttons do not. How can you check whether MOST is to blame?
COMAND NTG2 shows the menu and works from the steering wheel, but does not respond to the buttons? See how to use a loop test to check MOST and the telephone module before repairing the radio.
What should you watch out for when handing over a radio or navigation unit to an electronics technician without OEM specialisation?
Handing a radio or navigation unit to a general electronics technician is only really safe for simple power or audio faults. In OEM systems, the problem is often not the failed component itself, but the linked…
When does car amplifier refurbishment make economic sense?
Car amplifier refurbishment makes sense when you know what has actually failed. The most expensive mistake is replacing a module without checking the power supply, communication and the speakers themselves. In factory systems, a lack of…
Repair at a specialist workshop or an authorised dealer — what are the differences for OEM radio and navigation systems
Choosing between an authorised dealer and a specialist service changes not only the cost of the repair, but also the way the root cause of the fault is traced. In OEM radios and navigation systems, the problem rarely concerns only…
When does car electronics repair require experience in a narrow OEM specialism?
Car audio and navigation electronics are increasingly operating as part of the vehicle’s entire system. If a module is linked to the VIN, equipment coding or the CAN, LIN or MOST bus,…
Why are modern OEM multimedia systems harder to repair than older radios?
Older radios could often be repaired as a single unit: you checked the power supply, the power amplifier and, if needed, the code. In a modern OEM system, the same symptom can have several sources…
Why are audio fault symptoms in a car often mistaken for a battery issue?
Symptoms such as the radio resetting, a black screen after starting the engine, or no sound after start-up often point attention to the battery. That is logical, because they usually appear with a voltage drop…
Why is corrosion dangerous for car amplifiers mounted in the boot?
An OEM amplifier mounted in the boot works low down, close to places where moisture can easily get in. An amplifier flooded in the boot can at the same time mute the audio, disrupt module communication and drain…
Is a used salvaged radio a safe choice for a driver?
A used salvaged radio can be a sensible replacement, but only if it suits the car not just mechanically. In many cars such a unit works with the onboard electrical system, the display and…
Why does simply replacing the unit with a used one not always solve an OEM radio problem?
An OEM radio rarely works as a completely stand-alone unit. If, after a fault, you buy a used unit without checking the car and parts compatibility, you may move the problem rather than remove it. In many…
What does the amplifier do in a car audio system?
The amplifier in a car is responsible for much more than just increasing the volume. If the radio starts up but there is silence from the speakers, one of the main suspects is the amplifier or…
How does factory car navigation work in a modern vehicle?
Factory navigation in a modern car works as part of a larger infotainment system, not as just a screen with a map. That is important, because the same symptom can result from damage to…
Why is it worth repairing the factory car radio instead of fitting an aftermarket unit?
A factory car radio is usually more than just an audio player. It supports the screen, navigation, Bluetooth, sometimes the reversing camera, parking sensors and some of the car's settings. That is why a fault in such a unit does not…