I've installed 2x 4GB sticks of memory (DDR3 10666CL9) in my Toshiba Portege R700 (PT314U) and am having boot problems, which are resolved when I switch back to the original memory (2x 2GB) or one stick of the new memory. Using 1x new and 1x old stick doesn't work either. I've run tests using memtest86 using both new sticks and get errors, but running the tests on each new stick individually comes up clean.
When both new sticks are installed and I power on the laptop, it turns on but the screen remains blank. Sometimes the CPU fan goes nuts (goes up to full speed and stays there). Other times the computer will power itself off after about a second, and will turn itself back on a few seconds later, and repeat this. After a bit of pulling out the battery and holding down the power button I can usually get the computer to boot, but then it only sometimes boots the OS (Ubuntu 12.04). If the OS does boot, everything works perfectly until I shut down and next need to turn the laptop back on.
The laptop is supposed to support up to 8GB of memory. I can't find anything in the BIOS related to memory settings. Any ideas would be greatly appreciated!
Edit: I've updated the BIOS to version 2.20 and everything seemed okay at first, but now I'm having the same problem again - when turning the laptop on, it will turn itself off again. After a bit of stuffing around I can eventually get it to power up and boot the OS, after which everything works perfectly. Any other advice would be very much appreciated.