Apple MD094LL/A manual Running diagnostics, replace, Optical drive

6.	Media that is out of balance	Yes	Media issue. No repair
	may not perform well at higher		necessary.
	speeds even though higher
	speeds may be supported
	by the optical drive. Verify if	No	Go to step 7.
	slowing requested burn speed
	allows discs to be written
	reliably.
7.	Test write data to compatible	Yes	Issue resolved.
	CD and DVD media. Verify
		No	Run ODD sensor and ODD fan
	burned media is recognized
			tests in ASD:
	and reads reliably.
			If errors found check
			ODD sensor and ODD fan
			connections to logic board
			(read/write errors may be due
			to drive being too hot).
			If no errors are found while	J03
			running diagnostics, replace
			optical drive.

2010-09-09 iMac (27-inch, Mid 2010) Symptom Charts — Mass Storage  81