MacBook freezes after RAM upgrade
Hello, Yesterday I upgraded my RAM from 2x 1GB sticks and added a 4gb RAM stick...so in total I have 5GB RAM.
When I click on 'about this mac' it shows up as 5GB RAM however sometimes it only shows up as 4.75GB or 4GB RAM- why am i losing a gig of RAM sometimes?
After the upgrade and I started to encounter problems. When I close the lid the macbook would restart by itself. Sometimes when I open the lid it just shows a black screen where I have no other option but to manually restart the macbook. What could I do to resolve this problem?
I have tried resetting the PRAM and the SMC, but no change.
Seems to me one of the ram modules may be bad or may not like being mismatched.
Most important things to note when installing ram:
1) NEVER touch the pins on the chip with your fingers, always hold the modules by the sides of the wafer.
2) ALWAYS be wary of ESD, make sure you are grounded or at least not wearing socks on the carpet when opening your computer and accessing ram.
3) It's not necessary, but most ram problems come from mismatching chips. Most ram today is sold in dual channel, 2 module packages (6 gb max ram usually forgoes this), but Macs seem to prefer matched module sizes. That said, I've installed a 4gb module with a 2 gb module in a computer one generation older than the one you listed and had no trouble at all.
Re-seating the ram is merely popping the modules out of the socket, perhaps blowing out the socket with a can of compressed air, then re-installing them carefully and evenly, being sure they are flat, flush, and fully inserted into the socket. Perhaps try running the 4gb module by itself and see if the problem persists. It may be that one of the original modules was damaged during your installation and could be causing the problem as well.
Good luck and let us know what you find.
Have you run Apples 'System Profiler' app to see what it reports about the memory you bought? You can get to the app via the 'About this Mac' menu choice under the Apple icon, then select 'more info' button. Slide down to the Memory listing and check your memory against your original memory it should have the same other than size.
Apple also released a quiet update to the EFI Firmware to address memory access issues (when using larger SIMM's) Using the Profiler App again check your firmware level when you click on the Hardware tab its self it should be MB71.0039.B0E If not go here Firmware Update 2.1
Okay seems like nobody answered you to help reset PRAM or NVRAM since it's particularly the issue over RAM replacement.
- Shut down the computer.
- Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
- Turn on the computer.
- Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
- Hold the keys down until the computer restarts and you hear the startup sound for the second time.
- Release the keys.
Your computer's PRAM and the NVRAM are reset to the default values. If any PRAM or NVRAM congestion was causing such issue, it should have been addressed by this attempt. Cheers!