installing used memory

No, but you do have to use the same spec'd RAM as is already in the machine. I suspect that isn't the case, hence the problem. The annoying beeping sound means bad RAM.

Yeah the specs for the 2012 and 2013 look identical

iMac (27-inch, Late 2012)

iMac (27-inch, Late 2012) computers have four SDRAM slots in a compartment located on the rear of the computer. The computer comes with at least 8 GB DDR3 SDRAM installed as two 4 GB DIMMs into two slots. The maximum amount of RAM you can install in your computer is 32 GB (an 8 GB SO-DIMM in each slot).

You can use any small-outline dual inline memory modules (SO-DIMMS) that meet all of these criteria:

• PC3-12800
• Unbuffered
• Nonparity
• 204-pin
• 1600 MHz
• DDR3 SDRAM

You can use RAM module sizes of 4 GB or 8 GB in each slot.

iMac (27-inch, Late 2013)

iMac (27-inch, Late 2013) computers have four SDRAM slots in a compartment located on the rear of the computer. The computer comes with at least 8 GB DDR3 SDRAM installed as two 4 GB DIMMs into two slots. The maximum amount of RAM you can install in your computer is 32 GB (an 8 GB SO-DIMM in each slot). You can use any small-outline dual inline memory modules (SO-DIMMS) that meet all of these criteria:

• PC3-12800
• Unbuffered
• Nonparity
• 204-pin
• 1600 MHz
• DDR3 SDRAM

Make sure the sticks were seated proberly.

Message was edited by: Frank Caggiano - Just to be clear the 2012 you are taking the memory from boots and works ok, right?

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