Laptop Memory Install gone wrong 2

[cobra111]

My Dell C840 Laptop now shows that 512mb of SODIMM Memory is installed. I should have 1 GB currently showing, how can this be ? I was very careful to use a grounding strap and the installation went very smooth. What could possibly be wrong ?

 

[wahnula]

Are you 100% sure the memory module is compatible? Is it new?

 

[cobra111]

I absolutely know that its the correct 200-pin(DDR)SODIMM Memory Module for the Dell C840 Laptop. The Memory is NEW from 4allmemory.com . I have bought from them before with perfect results. The one thing that I negelected to mention in my first post was that the C840 was not showing the correct amount of Memory before changing it. It had 512 mb (2 x 256 Modules) and the system showed that there was only 256 mb of total Memory. Very strange . . .

Steve

 

[Freestone]

If you now have 2 x 512 modules installed then you must have a bad memory slot since 2 x 256 modules showed only half the installed memory too.

 

[cobra111]

That actually had crossed my kind but didn't want to act on it or assume it. Is there a test that I can do from home (Software or Hardware) to test the individual slots ? If so could you advise me ? Thanks in advance

 

[Freestone]

I would think just trying one module at a time would show something. 512 (or 256 depending on what module you use) would show from one slot, no memory in the other.

 

[cobra111]

I hope I can do it that way as you have suggested, however I'm pretty sure that there is a dominate slot that always needs some thing in it correct? I may be wrong. I'll read up in the user guide and see if it is talked about at all. Thanks for your wisdom . . .

 

[jurgen36]

In the Dell 840 you can use either one of the two memory slots. It does not make any difference at all. I just pulled out one memory stick and it works the same on my Dell840. I then changed over to the other slot, again no problems. Suggest you check the Cmoss, I do believe the memory must be enabled. Good luck

Jurgen

 

[cobra111]

When you say that you suggest I check the Cmos what does that mean and how do I go about this task ? Conversely how do I check to see if the memory is enabled. Any direction at this point would really help. I'm somewhat savy to a point. I'm not an Electrical Engineer though. Thanks for your help and suggestions. . . .

 

[wahnula]

When you say that you suggest I check the Cmos what does that mean and how do I go about this task ?

First, see if both slots work. Take one stick out & boot. Change slots & reboot. Should work both times. If not, a slot is malfunctioning or disabled.

I'm assuming jurgen36 means the BIOS settings. I believe you can get into the BIOS in a Dell by pressing F2 or F10 during boot, there should be a prompt "press F(x) to enter setup" or the like. You might miss it the first time around, so reboot if you do. When you are in the BIOS there are many screens. Learn how to navigate around by following the instructions on the screen. You are looking for any setting that says "Memory", explore your options but change nothing without writing down what you did and where. Not having that unit it is impossible to know what you will see.

It should be fairly straightforward, if you see a setting like "Enable Memory II" or 'disable memory' that is what you are looking for.

Let us know what you find.

Tony

 

[cobra111]

As it turns out I was able to Flash the Bios to update them, however it didn't help the overall situation. I did however determine that Dimm slot "A" is defective by process of elimination with your suggestions. It also turns out that it is not possible to "Enable Memory" within the Dell Latitude C840, so I'm stuck with the new memory purchase of 1 Gig and really only able to use 512MB. The computer runs "OK" but should run much faster. Truth be known I learned a lot and I have all of you guys to thank. I really appreciate your wisdom wahnula & jurgen36.

Thanks a bunch both of you,
Steve

 

[Freestone]

Is your laptop still under warranty?