15-inch FW800 won't recognize lower RAM slot

[elbert]

I'm troubleshooting a PB for a friend. It's a 1.25 GHz 15" PowerBook from the UK (it's got a British keyboard layout).

At certain times, OS X would sort of hang, wherein the mouse moves erratically but will not select anything. Even Apple+Tab would not switch between open apps. Weird though that by closing the lid and putting it to sleep (it would take a bit longer than normal to get it to sleep though), and waking it up, everything would run normally again.

At first, I suspected it was the OS. So I went ahead and erased the drive and did a clean install of OSX.

That didn't solve it.

So i suspected it could be with the RAM or the APE card (I seen cases of loose cards causing similar problems). So I re-seated both RAM modules (2 x 256) and the APE.

Still didn't solve it.

I then started swapping the RAM, running one without the other, alternating between lower and upper slots.

Still no go.

I fired up Apple System Profiler and that's when I discovered that the LOWER slot was reported as empty, even if there was RAM in it. So I swapped the RAM once again. Same thing. I tried booting up with just one RAM in the lower slot, but it wouldn't go.

Obviously, it's the lower slot causing the problem. Either it's busted or I just didn't seat the RAM properly. I'm sure I did though, I even followed the DIY PDF from Apple.

My question: has anyone encountered a similar problem? Is there a DIY fix for this? Or would I have to take it to an ASP and have the logic board replaced?

Thanks in advance.

[Edited on 3-20-2005 by elbertc]

[Carlo]

Could it be bad RAM?
I remember having a similar problem with my Powerbook (remember when Niño, Vic and I first got ours?). It was very finicky with RAM. Either it won't boot-up or one of the slots was said to be 'empty'. I switched slots and booted numerous times but could not figure out if the problem stemmed from the module or the slots. Despite the switching, only one slot was said to be working. I thought my logic board was busted until I tested it on other brands of RAM. It only worked properly when Niño found those Kingston ones.

Maybe you could try borrowing someone's RAM for testing. Is that a rev A?


[Edited on 3-19-2005 by Carlo]

[Maccess]

I think you should read this thread:

http://www.macintouch.com/badram03.html#mar18

It reports on RAM related problems with the 17" AlBook.

These types of problems are rarely the fault of the logic board. The most common cause of these problems is faulty or wrong spec RAM.

Unfortunately, Apple has to bear the cost of needless logic board replacements because of faulty RAM.

[Edited on 3-20-2005 by Maccess]

[elbert]

Thanks for the link, Alex. Thanks for the tip, Carlo. Will do as suggested.

Here's some additional info. It's actually using two HYNIX 512MB modules, presumably installed by Apple (probably BTO). As mentioned earlier, I've tried booting up with just one module, in the lower slot, and it wouldn't startup. I've tried doing this with both modules.

Speaking of startup, I noticed that this PB does not have a startup chime, even though the volume is on and the speakers work. It's as if I've previously shut down in mute (or held down on the mute key while starting up). I've reset both PMU and PRAM and it still won't chime. I wonder if this could be related to the lower slot issue.

Thanks.

[Carlo]

Elbert, try another brand.
I remembered Hynix not working on mine. It was either Samsung or Kingston. Weird no?

PS
Yup. Mine lacked the start-up chime when using the strange RAM.

[elbert]

That's very comforting to hear (for my friend, that is). Thanks Carlow.

[Carlo]

Let's cross our fingers and hope that it is the same problem.

[hungryalien]

Originally posted by Carlo
Elbert, try another brand.
I remembered Hynix not working on mine. It was either Samsung or Kingston. Weird no?

PS
Yup. Mine lacked the start-up chime when using the strange RAM.

before the all samsung ram setup that am using right now, was using samsung-hynix setup with no problem..

its kingston that i had problem with..

strange.. hehe