In your case, I think that the length of the wires in proximity with the FM receiver, and with no shielding, is suspect.
Maybe, but cut wires at correct size and remove the tip would be a big pain to complete 72 LEDs * 3 ^^ so i have used a simple wire to do it fastter and smaller.
And its big frequency since i can cath a choke by touching it (5v).
still it get a paper cover, wires are not uncovered, paper not a big help but protect me from choke ^^
Such problems can be solved, but prepare yourself for a tough time. You can't limit the drive signals to the LEDs because they depend on high speed to work. All you can do is try to keep the signal away from the receiver.
Since LEDs is a separate module i will try put it next to the case, 40cm away from mainboard.
Does the FM receiver have an antenna?
Is there adequate power supply isolation between the LEDs and the receiver?
Yes and Yes.
Antenna is a 20cm cable with 3 wires inside. (Only one used)
Power supply is a switching 5v 5a power adapter.
Here power tips from fastled:
Some of these are just good engineering. Some are just plain voodoo. Use whichever ones that work for you.
At the 'far' end of long LED strips, connect the Data line to Ground.
Insert a 200 ohm resistor between the output pins on the microcontroller and the inputs (data, clock) on the LED strip.
Use a level-shifter to raise the voltage of the output pins' 3.3 volts to a full 5 volts before sending it into the LED strip's data (and/or clock) inputs.
i havent done that bold tip, should i?
NOTE: this pop sound is not a big issue or a uncomfortable problem, after switch to digital potentiometer over the analog pop sound goes a little soft/dimmer. But i want to know his source, solving is not a requirement but would be good