Dell Inspiron 6400 Laptop question

[Grumpybear2000]

I have a Dell Inspiron 6400 Laptop and when i try to put in more memory computer wont fire up. Up the top above keyboard in between media direct button and start button is a panel that has five items that light up. Usually 3 light up from left side then go out and the fourth one (wifi) only stays on. When i add more memory the first 3 from left side come on and stay on and laptop freezes up with a blank screen.

[manker]

It sounds like the extra memory stick you put in are either incompatible with your laptop's hardware or the stick itself is broken.

Did you check for compatibility before purchase?

[Artemis]

I have a Dell Inspiron 6400 Laptop and when i try to put in more memory computer wont fire up. Up the top above keyboard in between media direct button and start button is a panel that has five items that light up. Usually 3 light up from left side then go out and the fourth one (wifi) only stays on. When i add more memory the first 3 from left side come on and stay on and laptop freezes up with a blank screen.

You have to check first that the SODIMM modules are the same speed and also the same timing. If they are a different timing then they will be incompatible with each other and cause the system to freeze due to a memory check error. A way to ascertain this is to remove the original module and insert the upgrade module into the first slot instead of the original factory module. If the system boots with this module in but not with both then the problem is a timing error between the SODIMM modules.
If on the other hand when you remove the original SODIMM memory module and try and boot with just the replacement module and it either locks up or does not start up then the memory module is not compatible with your laptop.