Apple Imac Late2015 Essentials Manual

 Chapter 4    Find answers 51
Replace memory
Overview
You can replace memory in the 27-inch iMac by following the instructions in this section.
Important:  The memory in the 21.5-inch iMac is not user-replaceable and can’t be upgraded 
after purchase. The 21.5-inch iMac can have a maximum of 16 GB of memory installed. Do not 
attempt to open your 21.5-inch iMac to replace or upgrade its memory. 
Your 27-inch iMac comes with at least 8 gigabytes (GB) of 1867 MHz DDR3 memory installed as 
two 4 GB memory...

 Chapter 4    Find answers 52
Install memory in your 27-inch iMac
 1 Turn off your iMac by choosing Apple menu > Shut Down.
 2 Disconnect all cables and the power cord from your iMac.
 3 Place a soft, clean towel or cloth on your work surface. Hold the sides of your iMac and lay it 
down so that the screen rests on the surface and the bottom faces you.
 4 Open the memory compartment door by pressing the small gray button located just above the 
AC power port.
®
The memory compartment door opens as the...

 Chapter 4    Find answers 53
 6 Locate the levers on the sides of the memory cage. Push the levers outward to release the cage.
 7 Pull the levers toward you to give you access to the memory module slots. 
 8 Remove a memory module—handle it carefully by its edges and pull it straight up and out. 
 9 With the notch on the bottom and toward the right side, replace or install a memory module by 
inserting it into the slot. Press firmly and evenly until you feel a slight click.
74% resize factor 

 Chapter 4    Find answers 54
 10 After you’ve installed all the memory modules, push the memory cage levers down into the 
compartment until they click back into place.
 11 Replace the memory compartment door, then press it firmly.
 12 Hold your iMac by its sides and return it to a standing position. Reconnect the cables and 
power cord.
 13 Press the power button on the back of your iMac to turn it on.
Make sure your iMac recognizes the new memory
After you install memory, check that your iMac...

 Chapter 4    Find answers 55
To start Apple Diagnostics, restart your iMac and hold down the D key as it starts up. If prompted, 
select the language for your location. Press the Return key or click the right arrow button. The 
basic Apple Diagnostics test takes a few minutes to complete. If issues are found, a description 
of the issue appears with additional instructions. Make a note of any reference codes before you 
exit Apple Diagnostics.
Online resources. For online service and support...

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Safety, handling, and support
Important safety information
WARNING:  Failure to follow these safety instructions could result in fire, electric shock, or other 
injuries, or damage to your iMac or other property. Read all safety information below before 
using your iMac.
Handling. Set up your iMac on a hard, stable work surface that allows for adequate air circulation 
under and around the computer. Never push objects into the ventilation openings. Your iMac can 
be damaged if dropped, burned,...

 Chapter 5    Safety, handling, and support 57
Hearing loss. Listening to sound at high volumes may damage your hearing. Background noise, 
as well as continued exposure to high volume levels, can make sounds seem quieter than they 
actually are. Use only compatible earbuds, headphones, or earpieces with your iMac. Turn on the 
audio and check the volume before inserting anything into your ear. For more information about 
hearing loss, see www.apple.com/sound.
WARNING:  To prevent possible hearing...

 Chapter 5    Safety, handling, and support 58
Important handling information
Operating environment. Operating your iMac outside these ranges may affect performance:
 •Operating temperature: 50° to 95° F (10° to 35° C)
 •Storage temperature: -4° to 113° F (-25° to 45° C)
 •Relative humidity: 5% to 90% (noncondensing)
 •Operating altitude: Tested up to 10,000 feet (0 to 3048 meters)
Do not operate your iMac in areas with significant amounts of airborne dust, or smoke from 
cigarettes, cigars, ashtrays,...

 Chapter 5    Safety, handling, and support 59
Understanding ergonomics
When you use the keyboard and mouse, your shoulders should be relaxed. Your upper arm and 
forearm should form an angle that is slightly greater than a right angle, with your wrist and hand 
in roughly a straight line.
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This
Not this
This
Change hand positions often to avoid fatigue. Some computer users might develop discomfort 
in their hands, wrists, or arms after intensive work without breaks. If you begin to develop...

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FCC regulatory compliance
This device complies with part 15 of the FCC rules. Operation is subject to the following two 
conditions: (1) This device may not cause harmful interference, and (2) this device must accept 
any interference received, including interference that may cause undesired operation.
Note:  This equipment has been tested and found to comply with the limits for a Class B digital 
device, pursuant to part 15 of the FCC Rules. These limits...