CD73 doesn't turn on

[Repinator]

Alpine CD73 Professionnal , the cd does load and eject, the lights come on with driving lights but the rest of the radio doesn't work , no sound.
I checked all the fuse, there is 12V coming to the radio
I did not find any defects.
Can anyone help me?

[MrRepair]

Remove main PCB and turn it over. Look for 5V rail pico fuse. Its by the emitter of Q821 and is marked with a M. Its open circuit - replace. You can check the one on the 8V rail too. Its on the emitter of Q823.

[Repinator]

Remove main PCB and turn it over. Look for 5V rail pico fuse. Its by the emitter of Q821 and is marked with a M. Its open circuit - replace. You can check the one on the 8V rail too. Its on the emitter of Q823.

you were right,5v pico fuse damage.
this radio starts on the table,or just on the car?

Thanks!

[MrRepair]

You can test everything on the bench. If you get no sound the car may have an amplifier.

[Repinator]

After I deleted both eeprom cd starts but the display is visible in the fog.

[MrRepair]

Both IC512 & IC603 must be loaded. You have deleted the setup data. Can you restore the original or copy from another unit ?

[Repinator]

I have the original data, but it doesn't start with them

[MrRepair]

Try these: BMW.rar

[Repinator]

With your dump it works

Thank you very much sir!

[MrRepair]

You can check everything in service mode:

Switch radio ON.
Within 10 seconds hold M button in for 8 seconds.
Service menu will display.
Navigate with + & - buttons

Be careful not make changes you don't understand.

[ThankYou]

Remove main PCB and turn it over. Look for 5V rail pico fuse. Its by the emitter of Q821 and is marked with a M. Its open circuit - replace. You can check the one on the 8V rail too. Its on the emitter of Q823.

Thank you MrRepair. My BMW Radio stopped working last week. It didnt power on anymore, but it was capable of inserting and exiting CD's. I tried your advice with Q821 and i found an smd part, which was labeled with an M, but was 1 cm away from Q821. I tested the "M" part with an multimeter and it worked, so this part wasn't damaged. After a while i saw a part with the lable "F" next to the Q821, when i tested that one, there was no continuity so i tried to bridge that part with a wire. After doing this my Radio started working again. So if the "M" part is not broken, it could be the "F" part. Thank you very much for your advice

[MrRepair]

You're welcome. Stay safe.

[Dr Alex]

Remove main PCB and turn it over. Look for 5V rail pico fuse. Its by the emitter of Q821 and is marked with a M. Its open circuit - replace. You can check the one on the 8V rail too. Its on the emitter of Q823.

MrRepair,what amperage should i use for this fuse?
thanks

[MrRepair]

******** 300 ma.

[electro10]

******** 300 ma.

for both fuses?

And thank you by your information, I have the same solution and was the fuse!