Installing RAM help!!!

I just installed a new 1gb stick in my G4 Powerbook which already had a 512 stick........rebooted and my computer is saying that I have 1gb of memory. Should I have 1.5gb if I have both sticks in? Thanks

short answer is yes

I'm pretty sure both sticks have to be the same (in speed, and memory), or only the bigger one works.

That's what I think I've heard before.

they don't have to be the same.. it just improves the ram a little bit more when you have two of the same.

Is the new module double sided and identical rating and speed to the 512MB as it sounds like it is only reading one side of the module.

Also check the 512 module is seated nice and tight as sometimes they can become loose.

Also you might try just the 1GB module and see if it shows up as 1GB.

The 512 module came in the computer already (512 pc2-4200s), the 1 gb module is pc2-5300. Also, I just placed the 512 module back in by itself and it's not working at all!!! The 1 gb stick works fine in both slots.

What could be the issue here? Thanks!

So the 512 will not work all by itself anymore? Is there any way you damaged it taking it out? If the 1GB works in both slots, something is going on.

On my iMac G5 was like that and I also went with a faster DDR2 stick and it works great. Just for the record.

Good news/bad news: you successfully diagnosed the problem. Ram chips can fail for many reasons and the 512 is gone. At least it isn't related to the ram slots on the mobo. And it does give you the opportunity to get a matched pair!

The 512mb on the Powerbook was built into the logic board if I remember right.

Either someone screwed up somewhere along the way and one of 2 things happened:
-The module you got had the wrong SPD program and thinks it is a 512mb module
-You were given a 512mb module labeled as 1gb by mistake

The alternative is ESD somehow fried the chip on your logic board but didn't damage anything else, or some sort of strange issue with the memory controller. I can't really think of anything else off the top of my head that would cause that.

EDIT: Also, apparently when DDR is dying it sometimes goes slowly (half at a time). It may just be the module is bad. What brand is it?