10-10-2017 12:39 PM
I have upgraded my lenovo ideapad 510-15isk from 8gb ram to 12gb ram and the laptop origanaly said installed memory (RAM) 12.00 GB (11.9 GB usable) now after 4 days it says installed memory (RAM) 4.00 GB (3.88 GB usable) how can I fix this I have tryed reseting the laptop and reinserting the new 8gb ram stick and swaping back to the origanal 4gb ram stick but nothing has worked and also cpu-z recognises the 8GB ram stick But I just cant use it.
10-10-2017 01:53 PM
I presume that you are indeed running a 64-bit version of Windows, since you had 8GB to begin with, so the 4GB limit of a 32-bit OS should not be an issue.
If you enter Setup/BIOS, is the full amount of RAM recognized? If so, save and exit setup and see if Windows will now see the full amount of RAM. Try the same with your original 2x4GB configuration too.
If it is recognized by the BIOS correctly, then it is somehow being limited by the OS.
This is a long shot, but it is worth checking.
10-11-2017 04:28 AM - edited 10-11-2017 04:38 AM
If it is not being recognized in the BIOS, that rules out a Windows issue, so it must be a problem with the SODIMM slot itself, or the RAM since even the original 4GB is not being recognized.
Short of their being something wrong with the SODIMM slot that is preventing the RAM from being seating correctly, and thus is preventing it from being recognized, the only thing I could suggest is noting the current settings in the BIOS (e.g. the Security and Boot sections etc.), and then resetting the BIOS to its setup defaults (usually Fn +F9), restoring BIOS settings as needed, and then seeing if that resolves the issue.
If after resetting the BIOS is still not recognizing the RAM, then it is possible that either your RAM is bad, which seems unlikely, or there is a hardware issue.
There is a fairly recent BIOS update for your system (version 0XCN43WW dated 7/24/2017) so it may be something to consider applying if not already installed. It does not mention any specific fix for what you are seeing, and BIOS updates are always a bit scary, but if you do decide to do so, be sure to read and follow the readme.txt thoroughly.
Note: Before attempting the BIOS update, reboot the system, make sure your battery is fully charged, your AC Adapter is plugged in, and ensure that the system is stable before proceeding.
I wish I could offer more, but best of luck,