This is first time I am trying to upgrade the RAM on my Toshiba Satellite L650 Laptop running Ubuntu 12.04 64 Bit version.
After a little research about upgrading RAM I ordered a Kingston DDR3 module and it arrived today, I just installed it and booted. Now I had a total of 6 GB of RAM, 2 GB from the module I already had and 4 GB from the Kingston module I recently got. After booting the system Everything went fine and I logged into my user account. after that I noticed that a major set of hardware was not working on my system. System was not detecting the Cooling Fan, Wireless card, Ethernet card, Bluetooth, USB ports, e-Sata, in built Card reader, web camera and possibly many more things I didn't noticed. so basically, I was left with only the LCD, keyboard, Touchpad and the in-built speakers working in place. However the total amount of RAM was updated to 6 GB as I can see it while running
I was wondering if I pulled some wires off the board while installing the RAM but after checking it again I realized that was not the case. So I went ahead and pulled the new module off the board and rebooted. This time everything was fine and working as always. So now, when I had the clue about the problem I tried switching the slots for modules i.e. putting the 2 GB module into the one at which the 4 GB was installed and vice versa but again after rebooting I got only the keyboard, LCD, touchpad and in-built speakers working, nothing else was working.
Again, I tried putting only the 4 GB module and booted, Same thing again, Nothing was working just the keyboard, LCD.... So finally, I inserted only the 2 GB module and booted, It was all fine now. and this new 4 GB stick that I got recently is working fine on my friend's Asus laptop running windows 7.
Now I am wondering if there is any setting in Ubuntu 12.04 that I need to modify after upgrading the RAM ? Is it limited up-to the amount of RAM presented at the time of installation ? or at least any clue about whats going on with me ?