AVAudioPlayer gives no sound output

Yes, ARC was the problem for me too. I solved just adding:

In .h

@property (strong, nonatomic) AVAudioPlayer *player;

In .m

@synthesize player;

-(void)startMusic{
    NSString *soundFilePath = [[NSBundle mainBundle] pathForResource:@"Riddls" ofType:@"m4a"];
    NSURL *soundFileURL = [NSURL fileURLWithPath:soundFilePath];
    player = [[AVAudioPlayer alloc] initWithContentsOfURL:soundFileURL error:nil];
    player.numberOfLoops = -1; //infinite
    [player play];
}

Updated answer:

I've got the issue. It's with ARC and has nothing to do with prepareForPlay. Simply make a strong reference to it and it will work.

as stated below by user: Kinderchocolate :)

In code:

.h
~
@property (nonatomic, strong) AVAudioPlayer *player;


.m
~
@implementation
@synthesize _player = player;