Справочник Пользователя для Apple MD094LL/A

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

 2010-09-09

1.  Activity related shutdowns: 

Reset SMC and PRAM and 

verify that shutdown issue still 

happens.

Yes

Check with known-good 

bootable drive: go to step 2

No

Shutdown cause was related 

to SMC or PRAM programmed 

shutdown settings or 

corruption, and was resolved 

by reverting them to default 

settings.

2.  Booting from known-good 

bootable drive , verify that 

shutdown issue still happens.

Yes

Go to Power related 

shutdowns on step 3

No

Shutdown events do not 

happen on known-good OS.  

Reinstall Mac OS on customer 

hard drive,  update OS with 

latest version and check if any 

firmware update is available.

3.  Power related shutdowns: 

With known-good AC power 

cord and AC outlet, Verify if 

system continues to restart or 

shutdown

Yes

Go to step 4.

No

AC power cord / outlet issue. 

Issue resolved.

4.  Disconnect hard drive power 

cable from hard drive and 

startup the computer from 

other bootable media (like 

Install DVD, a same model 

computer in Target Disk Mode, 

or a compatible known-good 

OS on an external drive). Verify 

if system continues to restart or 

shutdown.

Yes

Go to step 5

No

Possible bad software or hard 

drive. Go to 

 symptom flow.

5.  Inspect and reseat AC inlet 

connection to power supply 

(the smaller of the 2 cables 

connected to power supply), 

and DC power cable from 

power supply to logic board. 

Verify if damage is observed on 

the cables or connectors.

Yes

Replace damaged cable. 

Retest. Return to step 1 if 

problem continues.

No

Go to step 6.

6.  Install known-good power 

supply. Verify if system 

continues to restart or 

shutdown.

Yes

Reinstall original power 

supply. Go to step 7.

No

Issue resolved with power 

supply replacement.