Apple Mac mini manual Audio Built-in Speaker Has Distorted Sound, M99

4. Open the Apple System Profiler.	Yes	IR Receiver reporting on USB
Selecting USB, do you see “IR		bus. Check for IR cable. Go to
Receiver” listed?		step 5
	No	Remove bottom cover, and
		fan, and reseat the IR sensor	X03
		connection to logic board.
		Replace any damaged IR
		sensor cable assembly. Go to
		step 5.
5. Remove bottom cover,	Yes	Take apart system to access	X13
disconnect AirPort antenna		the IR lens and sensor ,and
and remove shield, disconnect		verify that they are correctly
and remove fan and cowling,		installed and not blocked
then disconnect IR/LED sensor		by any foreign element. If
cable and connect a known-		correctly installed, replace IR
good sensor assembly to logic		sensor cable assembly.
board to verify that IR sensor
	No	Replace logic board (IR	M99
functionality is restored.
		controller is located on logic
		board).

Audio: Built-in Speaker Has Distorted Sound

Quick Check

Symptoms	Quick Check
Audio: Built-in Speakers Have	1.	Launch System Preferences and select Sound/
Distorted Sound		Output options. Verify that the sound output
• No audio from built-in speaker.		option is set to system’s internal speaker and that
• Audio from speaker is distorted		the balance control is set to the center position.
	2.	Obtain known good high quality sound file
		or use iTunes music store sound samples to
		evaluate sound quality. Verify suspect sound files
		on another system to determine whether the
		distortion is caused by the system or the sound
		file.
	3.	Set volume control to mid-range. Overdriving the
		built-in speaker can cause distortion.

2010-08-03 Mac mini (Mid 2010) Symptom Charts — Input/Output Devices  67