memory problem in laptop

S

SteelBlue05

Guest
I have a compaq presario 2600 laptop, its about 3 years old now.

It has two memory slots, 512mb each.

I can't seem to get the laptop to pick up the memory cards from BOTH slots at the same time. I have two 512MB cards in there, I have checked that each card works individually and that each slot works individually. But the recognised memory is always 512MB when I put the two cards in at the same time.

So its like each card is working, and each slot is working, but all together only 512mb is picked up.

Any ideas why that would be? The laptop has a max of 1024MB memory.
 
Ah - probably the same problem that I had here.

http://www.askmehelpdesk.com/comput...-k23-512mb-1gb-mem-upgrade-problem-13898.html
http://discussions.virtualdr.com/showthread.php?t=196044

The problem is that some PCs/laptops have very specific requirements of the memory DIMMs installed. For example (and very imprecisely) some can only deal with low density memory (e.g. chips on one side only) and others can deal with high density memory (e.g. chips on both sides of the DIMM). There can be other compatibility issues and, in my experience, the only safe way to guarantee compatibility (especially with laptop RAM) is to use a memory vendor's memory configurator to find compatible parts. Unfortunately I suspect that you will have to do what I did - buy more memory that is compatible with your laptop and sell on the others.
 
thanks clubman, I think its the same issue. One website recommends memory with 2700 something or other and the cards I have are 2100.

Not sure how I ended up buying the wrong ones. And the strange thing is sometimes when both cards are in it recognises the 1024MB but then later will go back down to 512mb.

thanks for the info.
 
SteelBlue05 said:
thanks clubman, I think its the same issue. One website recommends memory with 2700 something or other and the cards I have are 2100.
Click to expand...
That itself is unlikely to be the issue here. It would mean however that the PC2100 (133MHz) memory would be slower than what your laptop is capable of using (PC2700 or 166MHz) but they should still work. I suspect that he main issue here relating to why the laptop can only see half the capacity of each DIMM is the memory "density" issue (which may be related to the rank/bank issues mentioned in my posts on the other bulletin boards linked above). Try running some of the tools that I mentioned to interrogate your laptop hardware with the original and new RAM installed and see what they say.
And the strange thing is sometimes when both cards are in it recognises the 1024MB but then later will go back down to 512mb.
Click to expand...
Are you sure about that? That would be extremely odd!
 
Yeah - I ended up buying more memory that was guaranteed to be compatible from Crucial. I was able to sell on the other memory (via boards.ie now adverts.ie) that I had bought in the US and the memory originally installed to somebody else so it all evened out in the end (i.e. the upgrade cost me little or nothing other than a bit of hassle in selling stuff on).
 
ClubMan said:
That itself is unlikely to be the issue here. It would mean however that the PC2100 (133MHz) memory would be slower than what your laptop is capable of using (PC2700 or 166MHz) but they should still work. I suspect that he main issue here relating to why the laptop can only see half the capacity of each DIMM is the memory "density" issue (which may be related to the rank/bank issues mentioned in my posts on the other bulletin boards linked above). Try running some of the tools that I mentioned to interrogate your laptop hardware with the original and new RAM installed and see what they say.
Are you sure about that? That would be extremely odd!
Click to expand...

Yeah I used the scanning tool on http://www.crucial.com/eu/ and it said I have 2 slots with a capacity of 512 (2700) in each but I had only a 512 (2100) card in one of them. In fact I have 2 cards in there but it doesnt recognise one of them it seems.


results from the scan...
Currently installed memory:

slot 1: 512 MB DDR PC2100

slot 2: EMPTY


Each memory slot can hold DDR PC2700 with a maximum of 512MB per slot.*

*Not to exceed manufacturer supported memory.

  • Maximum Memory Capacity: 1024MB
  • Currently Installed Memory: 512 MB
  • Available Memory Slots: 1
  • Number of Banks: 2
  • Dual Channel Support: No
  • CPU Manufacturer: GenuineIntel
  • CPU Family: Intel(R) Pentium(R) 4 CPU 2.80GHz Model 2, Stepping 7
  • CPU Speed: 2791 MHz

And yeah even recently I put in a 512 card in there and the original 256 card and for a while it was showing 778MB or whatever from the properties on "My Computer". Its back to 512 again now though. I havn't a clue whats going on with that. I have ordered a 512mb 2700 card and will see if that works....
 
SteelBlue05 said:
Yeah I used the scanning tool on http://www.crucial.com/eu/ and it said I have 2 slots with a capacity of 512 (2700) in each but I had only a 512 (2100) card in one of them. In fact I have 2 cards in there but it doesnt recognise one of them it seems.


results from the scan...
Currently installed memory:

slot 1: 512 MB DDR PC2100
Click to expand...
Online memory configurators from Crucial and other vendors will normally make very specific recommendations as to what memory parts are compatible - down to specific make and model numbers. Just looking for PC2700 SO-DIMMs is not always sufficient for example (as I learned the hard way!).

Coincidentally I had a similar problem with desktop memory recently when I bought some PC133 RAM to upgrade my mother's ancient PIII 350MHz Dell Optiplex GX1* and it didn't work (because of the "memory density" issue) but thankfully it worked in mine and the memory in mine worked in hers so no loss.

* It may be ancient but it's sufficient for her needs especially now that I have ditched the now unsupported Windows Me from it and replaced it with Xubuntu.
 
It's not down at the moment if that's what you mean. I've never had problems with it but only visit it rarely.
 
Strangely enough, I've been getting a 'cannot display' message for some time (am shopping around for RAM at the moment) — but I found another one at .
 
There are lots of good vendor specific and generic online memory configurator websites out there. No harm in checking a few to see what they come up with when shopping for RAM.
 
Just tried the new memory card I got from Crucial.com. As expected it does work. And it does work in either of the two memory slots in the laptop. But as usual no two memory cards will work together. Only 1 of them is picked up.

Strange. I think I will just give up on trying to figure it out, already spent 200 euro on 3 memory cards. I can only get 512MB recognised out of the 1GB potential.

I also just tried putting back in the two orginal 256MB memory cards that came with the laptop but only one of those is being picked up. So its not a compatability problem, seems to be hardware?

Anyone any other ideas?
 
Perhaps it only works with identical parts in each slot (or have you tried that already)? I doubt it but perhaps there's a BIOS setting that controls how memory is handled? No chance you have a one non ECC and one ECC part? Try running Lavalys Everest 2.20 or CPU-Z on your laptop with the various combinations of memory parts installed and see what they report. Search around for information about memory part compatibility problems with your specific make and model of laptop.
 
Perhaps its your method of installing them. The memory really needs to be pushed in firmly. Which slot works?
 
Yeah I will try those links this evening.

The thing is both slots work, but not at the same time. Only one memory card is ever recognised. And I have tried two idential cards in the slots, I tried the two orginal 256MB ones but only 256MB was picked up.

Thanks for the help.
 
Sounds like the motherboard could be at fault! If you put in one 256 Meg card and one 512 Meg card you should be able to see which is the faulty memory slot. You may be able to see something obviously out of place with the faulty slot but in most cases I think that you might need to replace the motherboard.
The fact that you said it would sometimes recognise the two cards makes me think it could be something very slight like a lose wire or badly soldered connection, badly stripped wire touching another, ...
 
Afuera said:
Sounds like the motherboard could be at fault! If you put in one 256 Meg card and one 512 Meg card you should be able to see which is the faulty memory slot. You may be able to see something obviously out of place with the faulty slot but in most cases I think that you might need to replace the motherboard.
The fact that you said it would sometimes recognise the two cards makes me think it could be something very slight like a lose wire or badly soldered connection, badly stripped wire touching another, ...
Click to expand...

But both slots do work when I try a single memort card out in them. Thats where its odd.
 
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