Apple MD094LL/A manual X03, M23, X22, P17, M18, M08

7. Replace DC power cable,	Yes	Go to step 8
which supplies power to
logic board, hard drive, and
LED backlight board. Verify if	No	Issue resolved with DC power	X03
system continues to restart or		cable replacement.
shutdown.
8. Hardware-related shutdowns:	Yes	-If a temperature or a fan
Run latest available Apple		sensor failure is reported, go
service diagnostics and verify if		to step 9
a sensor failure is reported.		-If a voltage or a current
		sensor failure is reported test
		with known-good power
		supply board. If issue persists,
		replace logic board.	M23
	No	Setup ASD to loop test suite
		for burn in tests and go to
		step 9. If no failure is found
		after burn in tests, return unit
		to customer for no failure
		found.
9. Verify if a thermal sensor	Yes	-If fan not running failure,
or fan failure is reported by		check for fan cable seating
diagnostics.		and retest. If same failure
		after retest replace fan with	X22
		known-good fan and retest.
		If issue does not happen with
		known-good fan, replace
		user’s fan.
		-If an over temp failure
		reported, check for cause of
		over temp, like obstructed
		vent, dust in heatsink fin,
		clogged fan and retest. If still
		failing replace part where
		sensor is located (logic board,	M23
		power supply, hard drive or	P17
		sensor cable) according to	X03
		the sensor location table
		in General Troubleshooting
		chapter . Go to step 10
	No	Go to step 10
10. Isolate if issue solved	Yes	Issue fixed
Verify if shutdown/issue does
	No	Replace logic board with
is fixed..
		corresponding symptom:
		-if for thermal error cause	M18
		-if for other cause	M08

2010-09-09 iMac (27-inch, Mid 2010) Symptom Charts — Startup and Power  43