Step 7: Reconnect the cables.
Reconnect the power cord and any other cables you disconnected.
Step 8: Check the new memory.
Press the power button to turn on your Mac mini.
When you see the Mac OS X desktop, choose Apple () > About This Mac and check that the reported amount of memory is correct.
If the reported memory size isn’t correct, or if your Mac mini repeatedly sounds three tones, it’s having trouble recognizing a memory module. If this happens, shut down your Mac mini, verify the module specifications against the requirements listed on page 41, and then repeat the memory installation instructions to make sure the modules are installed correctly. If you still have problems, remove the memory and consult the support information that came with the memory, or contact the vendor who provided the memory.
