BMW F07 Top-HiFi audio amplifier

[tehmatix]

Hi,

I have problems to repair this device from a BMW X3 car. What I found is 4 components on the power inverter side off the amplifier which are not marked at all. All 4 items has a short between terminals 1 - 2.

Can someone tell me what components are those 4 ?

Thank you

[tehmatix]

Re: BMW F07 Top-HiFi audio amplifier

I keep locking onto board to understand how it works and I found a connections between output pins of UC28025D PWM controller. It's a short with a resistance value of ~20ohm between pin 11 and pin 14.
Still I don't have any clue what type of transistors can be all 4 .

[lotas]

Re: BMW F07 Top-HiFi audio amplifier

These are MOSFET transistors, they are in the inverter to get an increased bipolar power supply to the amplifier, there may be markings, just not visible, wipe the surface of the transistor with alcohol, acetone.

[lotas]

Re: BMW F07 Top-HiFi audio amplifier

I will add: Transistors there are 50N06-07L
When these Mosfets burn out, you need to check the entire wiring of these transistors and also replace the UC28025DW.

[tehmatix]

Re: BMW F07 Top-HiFi audio amplifier

Hi lotas,
Thank you so much for your response. I placed an order on Alixxxx for transistors and also can find a kit for repair on their site.
Waiting to come and a will keep update this post

[tehmatix]

Re: BMW F07 Top-HiFi audio amplifier

I replaced the PWM controller and 4 MOSFET transistors, working great