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PB G4 12" memory slot failed in Power On Self-Test but appears to be OK in OS X

C

chinderland

macrumors newbie
Original poster
Jun 25, 2006
13
0
Strange problem to me ...

I just replaced the hard drive in my Powerbook G4 12" 1.33GHz yesterday. This morning I found in System Profile (OS X 10.4.11) -> Diagnostics that the expansion memory slot failed the Power On Self-Test. However, the 512MB memory stick shows up in System Profile -> to be OK!

I also ran the Apple Hardware Test, which showed the RAM slot failed in start-up test (before I started the actual testing). After I ran Quick Test, however, the RAM Test passed as No Problem!

Anyone experienced this before? What could be the cause of the problem? :confused:

(Powerbook G4 12" 1.33GHz 768MB Mac OS X 10.4.11)
 
seems like a bad contact somewhere to me, could be the RAM is not seated properly, or it is failing, could also be the soldering of the RAM slot to the motherboard. you need to troubleshoot more, maybe try another RAM stick to eliminate possible causes.
 
deadpixels said:
seems like a bad contact somewhere to me, could be the RAM is not seated properly, or it is failing, could also be the soldering of the RAM slot to the motherboard. you need to troubleshoot more, maybe try another RAM stick to eliminate possible causes.
Click to expand...

Thanks for the advice! I will try to find another RAM stick and test it in my PB 12".

I was wondering if the problem did came from the soldering of the memory slot, how could it be that the OS can see and use the 512MB RAM (which appears as OK in System Profiles->Memory). Also the Apple Hardware Test passed the memory test stage and showed "No Problem", although it reported the problem from the Power On Self-test, too.

BTW, I just updated OS X to 10.4.11 yesterday, could this be a possible cause?
 
deadpixels said:
seems like a bad contact somewhere to me, could be the RAM is not seated properly, or it is failing, could also be the soldering of the RAM slot to the motherboard. you need to troubleshoot more, maybe try another RAM stick to eliminate possible causes.
Click to expand...

OK, I did try this: I took out the 512MB RAM stick from the memory slot and booted my PB. After system is up, I checked System Profiler -> Diagnostics. It shows that the Power On Self-Test passed.

So does this mean that the problem was caused by the 512MB RAM stick? Anyone? :confused: Thanks in advance!

Powerbook G4 12" 1.33GHz Mac OS X 10.4.11
 
chinderland said:
OK, I did try this: I took out the 512MB RAM stick from the memory slot and booted my PB. After system is up, I checked System Profiler -> Diagnostics. It shows that the Power On Self-Test passed.

So does this mean that the problem was caused by the 512MB RAM stick? Anyone? :confused: Thanks in advance!

Powerbook G4 12" 1.33GHz Mac OS X 10.4.11
Click to expand...

Do you have another stick of memory available to put into that slot? If so, try it and see what it does. If it tells you that it failed it might be the contacts in the slot or the contacts from the slot to the board. If not, the RAM module that you originally had in is bad.
 
Warbrain said:
Do you have another stick of memory available to put into that slot? If so, try it and see what it does. If it tells you that it failed it might be the contacts in the slot or the contacts from the slot to the board. If not, the RAM module that you originally had in is bad.
Click to expand...

Thanks. I will get another stick next week and try again. Will post back then.

The 512MB stick I took out from the slot did not fit very tight in the slot. Actually no much force was needed to either insert it into the slot or take it out. It feels loose in the slot.

Powerbook G4 12" 1.33GHz Mac OS X 10.4.11
 
chinderland said:
Thanks. I will get another stick next week and try again. Will post back then.

The 512MB stick I took out from the slot did not fit very tight in the slot. Actually no much force was needed to either insert it into the slot or take it out. It feels loose in the slot.

Powerbook G4 12" 1.33GHz Mac OS X 10.4.11
Click to expand...

That could be the slot or the card itself...hard to tell. That was the only stick of RAM you had?
 
Warbrain said:
Just seems odd to me because I have too much RAM sitting around my home and no computers to use it in.
Click to expand...

Hi, Warbrain,

I wish I had some RAM sticks at disposal as you do. :)

There is a small EMI Shield in the memory card bay, fastened in place with a long screw. What's the function of this small part?

Should the arm of the shield touch the Memory Bay Cover or not? Could this be a possible cause of the problem?

Powerbook G4 12" 1.33GHz Mac OS X 10.4.11
 
Some more findings:

I forgot to check the marking on the RAM stick, and I just did it. It is actually a 1GB RAM module but was shown in Mac OS X as 512MB!!! :eek:

I bought this powerbook from a fellow student and I had previously thought it was a 512MB RAM stick in the expansion slot!

The marking on the RAM stick reads: MT16VDDF12864HG-335D2 ... PC2700S-2533-1-Z 1GB DDR333 CL2.5. Here you can see the picture online: http://www.memoryten.com/pc/000257/DDR-200p-PC2700-1GB/

If a 1GB stick was detected as 512MB in OS, does it mean that the RAM stick is bad? Anyone with experience on this?

Powerbook G4 12" 1.33GHz Mac OS X 10.4.11
 
chinderland said:
Hi, Warbrain,

I wish I had some RAM sticks at disposal as you do. :)

There is a small EMI Shield in the memory card bay, fastened in place with a long screw. What's the function of this small part?

Should the arm of the shield touch the Memory Bay Cover or not? Could this be a possible cause of the problem?

Powerbook G4 12" 1.33GHz Mac OS X 10.4.11
Click to expand...

I'm not entirely sure...
 
chinderland said:
If a 1GB stick was detected as 512MB in OS, does it mean that the RAM stick is bad? Anyone with experience on this?

Powerbook G4 12" 1.33GHz Mac OS X 10.4.11
Click to expand...

the only real way to check it would be to put this RAM stick in another laptop and see if it shows up as 512Mb or a Gig.
 
chinderland said:
There is a small EMI Shield in the memory card bay, fastened in place with a long screw. What's the function of this small part?

Should the arm of the shield touch the Memory Bay Cover or not? Could this be a possible cause of the problem?
Click to expand...

I dont think that's a shield...unless it says it in the manual.

I always thought it was to ground the chassis of the computer to the case. Otherwise your grounding screws for things like the LVDS or inverter cable would be useless.

In other words, yes, it should touch the metal cover.
 
deadpixels said:
the only real way to check it would be to put this RAM stick in another laptop and see if it shows up as 512Mb or a Gig.
Click to expand...

OK, it's clear now. I ordered a 1GB memory stick from Crucial Europe and just stalled it. It passed the power-on test and the Apple Hardware Test. I also tested the memory using MemTest OS X. Everything is OK.

In conclusion, it is the problem of the old memory stick that shows only half (512MB) of the total capacity. Obviously, it is not compatible with my Powerbook G4 12"

Powerbook G4 12" 1.33GHz 1.25G Mac OS X 10.4.11
 
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