Bad memory sticks can cause problems.

1. The m/b should set of an error code (a sequence of beeps) if they are faulty, missing, or placed incorrectly.
2. They can cause the computer to not start, but I would expect condition one to make an appearance (be heard).
3. The computer will start but it can freeze up at any time (often the same point in a particular game due to the memory location) because of faulty memory chips.

Mark