Apple MD094LL/A manual Device, replace audio cable, Output and verify that Internal

Deep Dive

Check		Result	Action	Code
1.	Verify if boot chime is present	Yes	Go to step 2.
	when system is powered
	ON. Make sure audio output
		No	Reset PRAM and retest.
	preferences are not set to mute
	and volume is set to mid-range.
2.	Make sure no cables are	Yes	Go to step 3.
	connected to external sound
		No	If “Headphones” is the only
	input/output ports. Go to
			available sound output
	System Preferences > Sound >			L11
			device, replace audio cable.
	Output and verify that “Internal
	speakers” is an available option.		If “Digital output” is the
			only available sound output
			device, reseat audio cable to
			logic board. If issue persists,	L11
			replace audio cable.
			If issue persists, replace logic	M09
			board.
3.	Go to System Preferences >	Yes	LEFT speaker and amplifier
	Sound > Output. Set speaker		circuitry OK. Go to step 4.
	balance 100% to LEFT speaker
	and play a known-good sound
		No	No audio in LEFT speaker.
	file. Verify if sound is generated
	by LEFT speaker and that sound		Go to step 7.
	quality is acceptable.
4.	Set speaker balance 100%	Yes	RIGHT speaker and amplifier
	to RIGHT speaker and play a		circuitry OK. Set Balance slider
	known-good sound file. Verify		to middle. Go to step 5.
	if sound is generated by RIGHT
	speaker and that sound quality	No	No audio in RIGHT speaker.
	is acceptable.		Go to step 7.
5.	Verify if user-reported audio	Yes	Issue no longer present.
	issue has been resolved.		Return system to user.
		No	Go to step 6.
6.	Boot system from Install	Yes	Go to step 7.
	DVD or another known-good
		No	Known-good boot volume
	bootable volume. Verify if issue
			works OK. Troubleshoot for
	still occurs.
			software issue. Isolate if issue
			is application-specific or a
			possible OS conflict.

2010-09-09 iMac (27-inch, Mid 2010) Symptom Charts — Input/Output Devices  99