Toshiba 2455 S305 Satellite 2455-S305/S306 User's Guide (PDF) - Page 234

234 If Something Goes Wrong Resolving a hardware conflict Incorrectly connected or faulty memory modules may cause errors that seem to be device-related. It is worthwhile checking for these first: 1 Turn off your computer according to the instructions in "Turn Off or Shut down command" on page 102. 2 Remove the memory module, following the instructions in "Removing a memory module" on page 66. 3 Reinstall the memory module, following the instructions in "Installing additional memory (optional)" on page 60, and making sure it is seated properly. 4 Check for the error again. 5 If the error recurs, remove the memory module entirely and check for the error again. If removing the memory module eliminates the error, the memory module may be faulty. If the error recurs without the memory module installed, the error is not caused by the memory module. TECHNICAL NOTE: You must have at least one memory module installed for the computer to work. Power and the batteries Your computer receives its power through the AC adapter and power cable or from the system batteries (main battery and real-time clock (RTC) battery). Power problems are interrelated. For example, a faulty AC adapter or power cable will neither power the computer nor recharge the batteries. Here are some typical problems and how to solve them: The AC power light does not come on when you plug in the AC adapter and power cable. Make sure the AC adapter and power cable are firmly plugged into both the wall outlet and the computer.