Problems installing RAM

[homer]

I fully appreciate all the help the last time I asked about my RAM problem. I am I need of a little more assistance, so please indulge me. I have purchased a PC133 256MB RAM chip to replace or add to my current RAM, 128MB. I am not sure if the old chip is PC133 or PC100 or something else. My motherboard has only two slots for RAM. I have checked the manuals as well as the web sites offered on my last post.

The computer is a Compaq Presario, model number 7994.

When I tried to install the new chip I could not get the computer to boot back up. it just stopped at that “Compaq” screen. I have tried the chip in both slots; I have tried it with the other chip and without the other chip. Nothing seems to work. If you can help, I am grateful.

In the other post someone mentioned something about BIOS. I have no idea how to alter a BIOS, or access one. I am not entirely sure what it is. [img]graemlins/awcrap.gif[/img]

[Vaskez]

There're 2 possibilities:

1) Your motherboard doesn't support 133MHz RAM (PC133).
2) Your BIOS doesn't support it.

BIOS is the Basic Input Output System
It's basically like a low-level operating system. (Low-level means close to the hardware). It checks that all your devices like graphics card and keyboard are attached and then looks for an operating system and loads it. It also handles all hard disks and RAM. So what you need to do is boot your computer and look to see what logo appears. You could have a PhoenixBIOS or American Megatrends or whatever. The logo should be displayed on boot-up. Also check the version. You can press the Pause/Break key (above page up) to pause the screen while you write down the info. Then do a search for this BIOS versio on www.google.com.

Or post this info back here and I'll give you a hand.

Anyway, to upgrade your BIOS you will need to download the new version then follow the instructions which will involve running the BIOS set-up program from a floppy disk. In case you are wondering, the BIOS is stored on a CMOS chip (Complementary Metal Oxide Semiconductor) and that is why you can't get at it like you can get at windows which is on your hard disk.

Like I said, it could also be your motherboard (mobo) in which case you can't really do much except buy PC100 RAM or get a new motherboard. My 2 year-old motherboard needs PC-100 RAM. It should tell you in your computer's manual in the upgrading section.
You can find out which motherboard you have by looking for the motherboad ID string which is also displayed at boot up. It will be a long number (like 20 digits or something)above where your RAM gets counted up. You then have to go onto a motherboard ID site and type the number in and it should tell you if it's a well-known make and model. Then you can find info on it.

[ 01-08-2003, 04:12 PM: Message edited by: Vaskez ]

Good luck, I wish I could help, but the best thingyou could probably do is take the machine to a reputable service center. Unfortunatley they don't discourage people who don't know enough about computers from doing these kinds of upgrades. Hope no permanent damage was done.

[Garnet FalconDance]

Keeping in mind that I am far from a pc genius---there are machines that must have a matched set (parity) of ram---*2* 128 sticks instead of a single 256. It's possible that your machine is one of these. And as far as 100 vs 133 goes, (crosses fingers she remembers correctly) usually PC133 is backwards compatible with PC100 tho it'll only run as fast as your BUS speed.

[Vaskez]

Originally posted by Garnet FalconDance: Keeping in mind that I am far from a pc genius---there are machines that must have a matched set (parity) of ram---*2* 128 sticks instead of a single 256. It's possible that your machine is one of these. And as far as 100 vs 133 goes, (crosses fingers she remembers correctly) usually PC133 is backwards compatible with PC100 tho it'll only run as fast as your BUS speed.

I wasn't talking about the 133 not being compatible with the 100. I was talking about the motherboard not supporting 133.

[andrewas]

I *hate* compaq. Ive never worked in a Compaq machine without some kind of trouble somewhere. Inclduing a nasty gash off of cheaply machined steel. Did I mention I *hateHateHATE* compaq?

Right, lets think about this. Any time you have the new chip in, the machine wont boot. First thing we think about is a defective chip. Do you have access to another machine that you can get into? Preferably one thats owned by someone who knows this sort of stuff. If so use that to check it out. Its rare but sometimes the chip just wont work.

I dont think Vaskez' theory of not being able to run PC-133 applies, since the memory site I showed you did recommend a PC-133 chip. Also as I said, specs say PC133 should always work in a PC100 machine.

http://www.wimsbios.com/ has a facility for IDing a mobo from a BIOS number. Once you have the specs on the mobo itself we should be able to see if there are any good reasons for it not working.

[Sir Krustin]

Originally posted by Vaskez: I wasn't talking about the 133 not being compatible with the 100. I was talking about the motherboard not supporting 133.

The point is, it doesn't matter. If the BIOS doesn't support PC133 the memory will run as PC100 memory transparently. PC133 is backwards compatible with PC66 and PC100.

The problem likely lies with the way the compaq mobo uses the DIMM. I suspect that the slots must be used with the same size DIMMs in both slots.

[homer]

I have tried a number of times to read what the BIOS number is. I have been unsuccessful, either it flashes by at a point I cannot see or it just dose not show it. I tried to pause the screen, as suggested, however I was still unsuccessful.

When I take the computer out of its case I can see, on the motherboard, a label. It reads: Replaced with Compaq spare SPS-BD. 1394 motherboard 166049 – 101.

The original RAM chip is PC100 128MB. The one I am tried to install is PC133 256MB.

When Sir Krustin suggested that the same size chip must be in both slots I considered that the web site indicated that the computer could take 384MB of RAM; If I understand correctly the only way to obtain that would be with two chips, one 128MB the other 256MB. As such, I have tried to install both chips, in both slots. Either way it did not work. As for having both chips installed, I would be happy with just the one chip, the 256MB chip. I am so confused.

[Sir Krustin]

Can you get into bios (hardware) setup? Usually pressing the DEL key (or sometimes F1) gets you into the BIOS. Some BIOSes display information about the mobo, such as serial numbers, in setup.

[homer]

I have downloaded a program that was to tell me my BIOS name and version. When I ran it, however, it was in German . If I can decipher correctly I have a :

Phoenix BIOS version 2.10 32-bit-PC1-BIOS

I do not know if these are the numbers that are needed.

I have tried to find out some information about this BIOS on the web page mentioned above. I found my-self overwhelmed. I appreciate any more help.