3. Wait 15 seconds after computer

Yes

Go to AirPort Card Kernel

 

was powered down then

 

Panic symptom flow.

 

disconnect AirPort cable from

 

 

 

logic board. Verify if computer

No

Go to step 4.

 

starts up properly now.

 

 

 

 

 

 

 

4. Startup with Alt key to select

Yes

Go to Hard Drive Not

 

and start from the Install DVD

 

Recognized symptom flow.

 

inserted in the optical drive,

 

 

 

or from an external bootable

 

 

 

No

Go to step 5.

 

volume connected. Verify if

 

 

 

 

computer starts up properly

 

 

 

from alternate bootable

 

 

 

volume.

 

 

 

 

 

 

 

5. Disconnect optical drive cable

Yes

Reconnect optical drive and

 

and retest. Verify if computer

 

go to Optical Drive Not

 

starts up properly now.

 

Recognized symptom flow.

 

 

 

 

 

 

No

Go to step 6.

 

 

 

 

 

6. Remove coin battery on back

Yes

Issue resolved by logic board

 

of logic board (you will need

 

reset. Measure DC voltage on

 

to completely remove logic

 

battery touching battery with

 

board to do this), and leave out

 

red probe, and grounding

 

for approximately 1-2 minutes.

 

with black probe. If voltage is

 

Then reinstall battery. This

 

2.7v or less, replace battery.

 

will reset logic board. Verify if

 

For multimeter help, see

 

computer starts up properly

 

 

 

kBase #HT3250: Diagnostics:

 

now.

 

 

 

Using a digital multimeter.

 

 

 

 

 

 

 

 

 

No

Replace logic board.

M02

 

 

 

 

2010-09-09

iMac (27-inch, Mid 2010) Symptom Charts — Startup and Power  38

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Apple MD094LL/A Go to AirPort Card Kernel, Go to Hard Drive Not, Go to Optical Drive Not, Using a digital multimeter, M02