Adding memory won't work

alanack · Apr 1, 2003

Quote from abducens:

If the mb beeps on power up but then stops he may need to set the bios to defaults then see if the memory is found. Just a thing to try.

He did mention that the computer beeped when it started up. I'll have him do this when I talk to him. Thanks.

Alan

trader3 · Apr 1, 2003

Quote from alanack:

I sold a PC133 256Mb card of memory and a PC133 128Mb on ebay, and the guy I sold it to is having problems. His cpu won't start up with the new memory installed. Any ideas? This happened to me once, and simply removing it and reinstalling it solved the problem. But is there a setting that has to be changed? Thanks.

Alan

Hi,

IBM models can be very picky in the memory they need.

Some possibilities are:

1) incorrect memory type for his machine
2) memory incorrectly inserted
3) the bios could be incorrectly set for that RAM
4) his machine may require PC100 memory
5) the two memory types are incompatible on his machine
6) his machine may not take 256 MB sticks or may max at 256 MB RAM
7) unlikely but one or both memory sticks could be bad

If the bios is correctly configured and his machine takes PC133 memory, have him try to start the cpu with one RAM installed and have him switch the RAMs to try it both ways. Also have him try different slots.

It is a hassle, but you can go to the IBM website and look up what specific memory is required for his machine and check to see the memory is that kind. You could also check to see the both of your machines use exactly the same memory part number.

Hope that helps!

Sanjuro · Apr 1, 2003

The number of beeps tells you what error to look for in the motherboard manual.

Try the individual sticks ALONE to see if it's just a problem with a certain stick or compatibility issue.

Example: Plug in 256 memory and see if it books, then 128.

Good Luck!

alanack · Apr 1, 2003

Quote from trader3:

Also have him try different slots.

Doesn't memory have to be in slot #1, and then continuously from that point on? In other words, you could have memory in slots 1 and 2 but leave 3 empty, but you cannot put memory in slots 1 and 3 and leave 2 empty? Thanks.

Alan

TGregg · Apr 1, 2003

Quote from trader3:

4) his machine may require PC100 memory

As I recall, PC133 is backwards compatible with PC100.

Another possibility is he took them out of the bag, then walked across carpeting in his wool socks (with the memory in hand) and shorted them out.

TGregg · Apr 1, 2003

Quote from alanack:

Doesn't memory have to be in slot #1, and then continuously from that point on? In other words, you could have memory in slots 1 and 2 but leave 3 empty, but you cannot put memory in slots 1 and 3 and leave 2 empty? Thanks.

Alan

Some mainboards are like that.

gnome · Apr 1, 2003

Quote from alanack:

Doesn't memory have to be in slot #1, and then continuously from that point on? In other words, you could have memory in slots 1 and 2 but leave 3 empty, but you cannot put memory in slots 1 and 3 and leave 2 empty? Thanks.

Alan

Not necessarily. Try and see. One of mine currently has sticks in #1 and #3.

alanack · Apr 1, 2003

Quote from nkhoi:

sound like either bad or incompatible problem.

You were right. My ebayer's computer has PC100 memory. Someone suggested that PC133 should still work. But it seems pretty clear that it's incompatible, at least in this situation. My next question... Could he have damaged the memory by trying to run it in his machine? Thanks, and thanks to all who tried to help(this poor bozo) today. I appreciate it.

Alan

nkhoi · Apr 1, 2003

I guess not, I make that mistake frequently and no board has ever die on me.

TGregg · Apr 2, 2003

According to this site:

http://www.dewassoc.com/performance/memory/pc100_std.htm

PC133 should work in a PC100 system.

"Are different speed SDRAM backwards compatible?

To a certain extent, yes. You can use PC133 memory in a PC100 system and you can use PC100 memory in a 66MHz system, subject to the specifications of the motherboard. However, the memory will only run as fast as (A) the capability of the motherboard, and (B) the slowest memory present in the system. As an example, a PC133 module will run at PC100 speed in a system with a 100MHz Bus, or if there is a *compatible PC100 module already present, it will only run at 100MHz."

It's not rocket science. The main difference between pc133 and pc100 is that the 100 and 133 indicate max supported bus speed. It's like some athlete and I going for a walk. I can't run as fast as him, but he sure can walk at my pace.