One of my dimm slots keeps getting Knocked out

I have a curious problem with one of my memory slots.

Dimm slot_A works fine until I close my laptop lid which puts it in standby mode, when I open the lid the laptop works fine as Dimm slot_B still works but Dimm slot A is not available. When I do a scan for memory (don't remember what software I used to do it) it doesn't recognise that DIMM slot_A has a problem so no errors are brought up.

To temporarily fix the problem I have to shut down the laptop, take out the memory module from its slot for a couple of seconds then replace it. When I boot-up, the memory in Dimm slot_A works just fine until I close the lid to stand by my laptop and re-open it later as mentioned above.

Shouldn't memory either work or not work at all?
It is a Dell inspiron 5100.

 

Did you just recently upgrade your memory with new sticks?

Can you switch A to B slot to see if the A stick is defective? Or do they need to be 'in order'?

How about the seating of the stick, make sure it's in there firmly, sounds like closing the laptop could be moving the A stick.

Perhaps the slot is messed up...how are the little contacts, any bent? Try blowing out the slot also..

All I got for now......

 

"Did you just recently upgrade your memory with new sticks?"

Yes I swapped a 256 for a 512, plus I already have a 512 in DIMM slot_B. This problem started 6 months after the swap. I replaced the original 256 to see if the new 512 memory had died but the problem has persisted even with my original 256 that had always worked and still does as long as I don't put the laptop in stadby mode.

I've tried swapping the memory modules and the problem seems to be the slot. The contacts are OK it is a snug fit.

Don't know why putting it on standby mode knocks out the DIMM slot??

 

Just out of curiosity. Go to System properties. How much memory is shown there?
This may rule out any software hic-ups with what ever program you used and standby mode.

 

Reading what you wrote, I wasn't thinkin 'standby' was causing the prob, more thinking
the actual closing the lid is causing it...better than a bad slot..
else why would pulling the stick then
putting it back in all of a sudden make it work..
Sounds like something is losing it's connection...

Looked for any lose wires, have you dropped your laptop, slammed it shut,
is the top itself still in the position it was when you got it...could just be a small thing.

Try what ThunderZ says too...

How many slots do you have?

 

In System properties, when DIMM Slot_A isn't working it just gives the Mbs of memory in slot_B which is 512. It doesn't say 768 when dimm slot_A stops working even though there is 256 module in it. As I'm writing this post DIMM slot_A is working so I have 768Mb but I don't know how long this will last. Usually two or three stand-by and I'm back to 512Mb.

quintile,

I realise you meant physical problem but I don't think that is the case. The contacts are tight unless some other part of the slot is loose. No I've never dropped my laptop or slammed it shut. It cost me £1200 6 years ago and I intend to use it for another four. The lid is totally unconnected to the mem slots - they are no where near each other.
I will leave it on and shake the whole laptop now and again and to simulate moving it about the house and see what happens.

I think that it is a voltage spike that is too small to burn the mem module but high enough to stop it from working. Perhaps taking it out of its slot for a couple of seconds and placing it back in releases the extra charge build-up that stops it from working . This is a pure guess!