PCTech Forums

Hello all.

I just got a Compaq Presario 900 notebook computer from a buddy of mine that had a busted lcd screen. I replaced the screen and I am having a few issues..

First thing I did was run a game, and I noticed it was running a little slow, so I checked the RAM and realized it only had 256 MB (I'm running Windows XP Home). So I took a trip to best buy and picked up a generic 512 MB stick to add to it. (I made sure it was compatible via a website called Cruicial, and a program called Everest). I popped it in with the 256 stick already inside it, booted up, checked it out, and Windows is only recognizing 256 MB. So I thought maybe there was an issue with having two different size and brands of RAM, and I took out the 256 stick and replaced it with the 512, leaving the 512 where the 256 originally was. I turn on the laptop, and it won't boot at all, the lights come on but nothing at all shows up on my display.

I tried all different combinations of RAM, even leaving the original 256 in there alone, and it will not boot unless I have the 256 where it was originally WITH the 512 in there as well. The computer seems to run a tad bit faster (but maybe it's just my hopeful imagination), even though windows says I only have 256 MB.

By the way, the 256 stick and 512 stick both show up in Everest, although Everest contradicts itself by saying that my total physical memory is 256 MB.

Can anyone tell me what in the world is going on? I've never run into an issue installing RAM on a computer before, although I'm not at all experienced on laptops.

Thanks in advance

Dave_Lethal,

Laptops can be quite picky when it comes to ram, it could be something as simple as the wrong speed. You have to make sure you are getting the exact same thing. I usually take the laptop with me and pull out the ram right there on the counter. That way there is no question if it's right or not, just plug it in and boot the laptop right there on the counter.

I would first try the Compaq website and get the exact type of ram for your laptop. Make sure you use your laptop's Product Number like 900US or 900CA to find the right ram.

Next I would make sure that the ram you bought is the right type and speed called out from Compaq. Sometimes generic ram for a laptop will just not work even if it's the right type and speed.

So any idea why it won't boot if I take the 512 out?

Dave_Lethal,

It sounds like the BIOS has been automaticly set for both ram sticks and that is why it won't boot unless both sricks are in.

What does the BIOS say about how much ram is installed and can you rest this amount?

The bios doesn't say anything about RAM, which is weird. I went through the entire thing. It doesn't even say how much i have, let alone change the configuration.

Well I took the battery out before I put the 256 in this time and it did boot with the 256, but not with just the 512. The crucial website ran a diagnostics on my computer and said that the RAM should work, so either A: the memory stick is faulty (damn you Best Buy) or B: Crucial is wrong and I need a very specific type of ram. Or maybe C: my mobo is maxed out at 256 mb (I really hope this isn't the case)


Now I need to dig for my receipt

I would vote for either A or B especially if the laptop is "designed for Windows xp" or even "designed for 2000" because both recommend 256 or higher for ram and Compaq wouldnt have limited themselves to not allow for expansion. A would be likely if you can not boot no matter how hard you try from just the 512mb stick. B would be likely in many cases. I know that some laptop manufactures have very specific guidelines on what you can and can not put into your laptop includeing memory, many times your best bet is to contact compaq and purchase directly from them (which is why they do this).

I would check this site out your max memory is 1Gb DDR SDRAM of 133Mhz bus speed, which means option C can be eliminated.
http://www.xbitlabs.com/articles/mobile ... html#sect1

now you need to get your hands on a similar chip to see if the RAM is bad (option A) if the chip still wont be acknowledged you'll need to bite the bullet and purchase through compaq directly.

Dave_Lethal,

According to you need a 266MHz, PC2100, DDR-SDRAM DIMM memory module with a 2.5V core voltage.

If that is not what you got, find that receipt!

If that is what you got then most likely it's a bad ram stick.
I suppose that it could be the second connector slot on the laptop is bad, it could even be dirty for that matter.

So much for having the receipt, can't find it anywhere.

That was a waste of a hundred bucks. I'm never buying computer hardware from Best Buy again. My brother bought a wireless mouse the same day, and the left mouse button doesn't even work on it.

But anyway, I think the RAM was Kingston 512 MB pc2300, but on the box it said it was compatible with 2100, and I'm not sure what speed it was. I don't think the slot in the laptop is bad, it looks like it's in quite good condition, we'll see after I test it out with RAM I'm going to buy from Compaq directly.