False RAM detection

[superollie]

Hello,

My Dell Studio Laptop shipped with and still has 4GB RAM. Suddenly yesterday when I turned on, my RAM usage was unusually high. Turns out this is because it is only detecting 2 of the 4 GB that are installed. task manager and a few other pieces of software that I have all say 'total physical memory is 2GB'.

What can I do? Like I say, there are 4GB installed and I haven't removed any so WTF is going on?

cheers

Windows 7 professional 64 bit
Intel core i7 720 1.6GHz
4GB DDR3 1333MHz
ATI Radeon HD 4500

 

[MindoverMaster]

Does your BIOS see the 4GB? If so, it may be one of your sticks are bad.

If your BIOS does see 4GB, run memtest86+ on it. It's a bootable CD. Run at least 2 passes. Any errors, one may be bad.

If your BIOS does not see the full 4GB, try swapping each stick, one at a time, to see if one stick is bad. It simply won't POST if only one is bad. Could be a bad RAM slot, too.

 

[bpm55]

I would download cpu-z and check it again. If it reports only 2gb. You may have a dead ram stick. Easy way to figure out which is bad is to open it up and take both out and insert one and attempt to boot. If it boots shutdown and try the other stick. One may have died or may just have gotten jarred loose.

 

[Digerati]

Easy way to figure out which is bad is to open it up and take both out

The "correct" procedure is to first UNPLUG the power from the wall and open the case. Then you must put you and the computer at "the same potential" to discharge any static in your body by touching bare metal of the case before touching anything else. Now finally, you can remove the RAM.

Not unplugging from the wall (or setting master power switch on back of the PSU, if so equipped, to off), and not discharging any static is a sure way to destroy your RAM for good.

 

[kmote]

The "correct" procedure is to first UNPLUG the power from the wall and open the case. Then you must put you and the computer at "the same potential" to discharge any static in your body by touching bare metal of the case before touching anything else. Now finally, you can remove the RAM.

Not unplugging from the wall (or setting master power switch on back of the PSU, if so equipped, to off), and not discharging any static is a sure way to destroy your RAM for good.

IIRC "Dell Studio Laptop" don't have metal cases.

@superollie I would not recommend doing any work on the hardware (don't even open it up). Perform the software checks as indicated by mindovermaster and let us know the results. If there is something wrong, you should let Dell handle it under warranty.

 

[carnageX]

The "correct" procedure is to first UNPLUG the power from the wall and open the case. Then you must put you and the computer at "the same potential" to discharge any static in your body by touching bare metal of the case before touching anything else. Now finally, you can remove the RAM.

Not unplugging from the wall (or setting master power switch on back of the PSU, if so equipped, to off), and not discharging any static is a sure way to destroy your RAM for good.

Laptops don't have PSU's with a switch . The battery needs to be taken out of them.

 

[Digerati]

Sorry, brain flatulence! But still, even with notebooks, there is a metal chassis that is also system "ground" and that should be touched first to discharge any static in our bodies. And with notebooks, you don't just unplug, you remove the battery too before removing and inserting RAM.

 

[superollie]

thanks, the BIOS says 2 GB, had a very strange episode with this though...

After checking what the bios was saying I thought, since I was there, I might as well run some of utility tests to see if they flagged anything. I ran them and everything passed ok.

Then when logging back into windows the laptop bluescreened with a memory crash dump. Turned it back on and another mem crash dump and this time it went into repair mode for about 20 minutes and then restarted.

On the restart it began installing a load of updates. Now, I had done a windows update a few days before this but had restarted the laptop several time since then so assumed they were all already installed.

After the updates, I logged back into windows with no problems, checked task manager, and my 4GB were back! Total available memory - 4096! There was also a bubble in the bottom left saying that windows malicious software remover wanted to do a scan so I let it.

But now, after being at work all day, I'm home and it's only detecting 2GB again. I tried doing the whole lot again (Bios - diagnostics - restart) and exactly the same thing happened again - Bluescreen, repair mode - and then once back in windows it was once again reading all 4 GB.

So it seems like a consistent way of getting it to detect all 4GB is to induce a memory crash dump by way of the diagnostics test in bios (as detailed above).

I have also run memtest over night and no errors were found.

Any other ideas before I start testing individual RAM sticks?

thanks