Discussion:
Memory??? problems
(too old to reply)
Dick Sidbury
2006-05-01 20:52:44 UTC
Permalink
I got a PB G4 in oct more or less (the DDR2 version) and immediately got
a gig of memory for it. Recently with a few bucks in our fiscal year
budget left I got another gig. And now I'm having system problems:
kernel panic, system freezes up at random times...

I'm guessing that it's a memory problem but could be wrong. This morning
I took out both of the two 1GB memory modules and replaced them with the
original 512 and had no problems for the entire day (except for sluggish
response). When I got home I replaced the 512 with one of the 1GB
modules and will run that for a day. Then I will replace it with the
other one. If the intermittent problem does NOT show up, can someone
suggest a way of determining which if either memory chip may be at
fault. Or other suggestions about what else to try and diagnose.

I ruled out software problems based on rebooting from a backup firewire
disk and eventually running into the same problem.

dick
Gregory Weston
2006-05-01 21:34:43 UTC
Permalink
Post by Dick Sidbury
If the intermittent problem does NOT show up, can someone
suggest a way of determining which if either memory chip may be at
fault. Or other suggestions about what else to try and diagnose.
If you bought the machine new, it should have come with a diagnostic
disc that can identify which module, if any, has failed.
--
"Congurutulation!!!" - The subject line on some spam I received recently.
I have no idea what it means, but it's such a cool "word" (by which I mean
pronouncable sequence of letters) regardless.
Dick Sidbury
2006-05-01 22:21:35 UTC
Permalink
Post by Gregory Weston
Post by Dick Sidbury
If the intermittent problem does NOT show up, can someone
suggest a way of determining which if either memory chip may be at
fault. Or other suggestions about what else to try and diagnose.
If you bought the machine new, it should have come with a diagnostic
disc that can identify which module, if any, has failed.
I've run the diagnostic (TechTools Deluxe) three times. Twice if found
no errors and the other times the system froze while the program was
running. I'm guessing that the problem may be heat related, but of
course, that' just a guess.

dick
Stephen C.
2006-05-01 22:40:48 UTC
Permalink
Post by Dick Sidbury
Post by Gregory Weston
Post by Dick Sidbury
If the intermittent problem does NOT show up, can someone
suggest a way of determining which if either memory chip may be at
fault. Or other suggestions about what else to try and diagnose.
If you bought the machine new, it should have come with a diagnostic
disc that can identify which module, if any, has failed.
I've run the diagnostic (TechTools Deluxe) three times. Twice if found
no errors and the other times the system froze while the program was
running. I'm guessing that the problem may be heat related, but of
course, that' just a guess.
dick
Not from personal experience, but from what I've read, RAM can cause problems
while still reporting as 'good'. Swapping out modules is the acid test, of
course, but memtest has been talked about as a program for testing memory
modules. You might give this a try.

http://www.versiontracker.com/dyn/moreinfo/macosx/17156

StephenC
Gregory Weston
2006-05-02 00:28:08 UTC
Permalink
Post by Dick Sidbury
Post by Gregory Weston
Post by Dick Sidbury
If the intermittent problem does NOT show up, can someone
suggest a way of determining which if either memory chip may be at
fault. Or other suggestions about what else to try and diagnose.
If you bought the machine new, it should have come with a diagnostic
disc that can identify which module, if any, has failed.
I've run the diagnostic (TechTools Deluxe) three times. Twice if found
no errors and the other times the system froze while the program was
running. I'm guessing that the problem may be heat related, but of
course, that' just a guess.
No, not TechTool. New machines for the last few years have come with a
system diagnostic tool from Apple itself. The last couple of years it's
been on the same disc as the one that can restore your machine to the
factory software load. You boot off that disc - holding down option will
let you choose the diagnostic partition if it's also the system restore
disc - and run through a test suite from there.
--
"Congurutulation!!!" - The subject line on some spam I received recently.
I have no idea what it means, but it's such a cool "word" (by which I mean
pronouncable sequence of letters) regardless.
FPP
2006-05-02 05:08:25 UTC
Permalink
Post by Dick Sidbury
Post by Gregory Weston
Post by Dick Sidbury
If the intermittent problem does NOT show up, can someone
suggest a way of determining which if either memory chip may be at
fault. Or other suggestions about what else to try and diagnose.
If you bought the machine new, it should have come with a diagnostic
disc that can identify which module, if any, has failed.
I've run the diagnostic (TechTools Deluxe) three times. Twice if found
no errors and the other times the system froze while the program was
running. I'm guessing that the problem may be heat related, but of
course, that' just a guess.
dick
First, I wouldn't trust Techtool to detect memory problems... because it
doesn't.
I had a similar story, in regards to kernel panics. I was experiencing
more and more frequent crashes and panics on a daily basis. It got to
the point where I would install a fresh system, reboot, and just wait...

I tried Techtool, Diskwarrior, Drive Genius... none reported any
problems with anything, including RAM,

Invariably, the machine crashed with a kernel panic even if I never
touched a single key. I tried restoring from different backup sets, to
different partitions - and NOTHING worked. This went on for 3 straight
weeks day after day.

Until somebody told me to check my RAM again - with memtest. I was
extremely skeptical since I had the same 3 modules since getting the
machine 4 years ago.

To make a long story short, memtest disgnosed one of my 512 mods as
being bad. I still didn't believe it... but I took it out, and the
daily, hourly panics stopped.

It's been about 3 months now since I replaced the defective 512 module,
and I haven't had a single crash since. Not one.

Memtest gets my highest recommendation. It runs best in single-user
mode, and it can take quite a bit of time to finish... but it's worth
it. I let my test run overnight.

Good luck,

FPP
--
A pessimist says the glass is half empty.
An optimist says the glass is half full.
An engineer says somebody made the glass
twice as big as it needed to be.
Tim McNamara
2006-05-01 22:35:30 UTC
Permalink
Post by Dick Sidbury
I got a PB G4 in oct more or less (the DDR2 version) and immediately
got a gig of memory for it. Recently with a few bucks in our fiscal
year budget left I got another gig. And now I'm having system
problems: kernel panic, system freezes up at random times...
I'm guessing that it's a memory problem but could be wrong. This
morning I took out both of the two 1GB memory modules and replaced
them with the original 512 and had no problems for the entire day
(except for sluggish response). When I got home I replaced the 512
with one of the 1GB modules and will run that for a day. Then I will
replace it with the other one. If the intermittent problem does NOT
show up, can someone suggest a way of determining which if either
memory chip may be at fault. Or other suggestions about what else to
try and diagnose.
Have you tried memtest? There is a verision with a GUI wrapper, Rember:

http://www.versiontracker.com/dyn/moreinfo/macosx/24508
matt neuburg
2006-05-01 22:41:34 UTC
Permalink
Post by Dick Sidbury
I got a PB G4 in oct more or less (the DDR2 version) and immediately got
a gig of memory for it. Recently with a few bucks in our fiscal year
kernel panic, system freezes up at random times...
I'm guessing that it's a memory problem but could be wrong. This morning
I took out both of the two 1GB memory modules and replaced them with the
original 512 and had no problems for the entire day (except for sluggish
response). When I got home I replaced the 512 with one of the 1GB
modules and will run that for a day. Then I will replace it with the
other one. If the intermittent problem does NOT show up, can someone
suggest a way of determining which if either memory chip may be at
fault
Run memtest on it.

<http://www.memtestosx.org/>

m.
--
matt neuburg, phd = ***@tidbits.com, http://www.tidbits.com/matt/
Tiger - http://www.takecontrolbooks.com/tiger-customizing.html
AppleScript - http://www.amazon.com/gp/product/0596102119
Read TidBITS! It's free and smart. http://www.tidbits.com
Jon
2006-05-02 05:11:55 UTC
Permalink
Post by Dick Sidbury
If the intermittent problem does NOT show up, can someone
suggest a way of determining which if either memory chip may be at
fault. Or other suggestions about what else to try and diagnose.
In certain cases it may actually not be either module, but the
combination of modules..

An example is where you have two slightly different ram speeds. Many
machines will accept faster memory than specified, but may have problems
if you mix the standard speed and the faster one. There may be other
cases I didn't hear of, too. I recall there was a very strange thing
like that with some of the first TiBooks, where RAM that looked
perfectly OK on paper and that worked in some, didn't work in others.
Evidently there is more to ram chips than we mortals usually see...
--
/Jon
For mail address, run the following in Terminal:
echo 36199371860304980107073482417748002696458P|dc
Skype: storhaugen
Dick Sidbury
2006-05-03 01:16:31 UTC
Permalink
Post by Jon
Post by Dick Sidbury
If the intermittent problem does NOT show up, can someone
suggest a way of determining which if either memory chip may be at
fault. Or other suggestions about what else to try and diagnose.
In certain cases it may actually not be either module, but the
combination of modules..
An example is where you have two slightly different ram speeds. Many
machines will accept faster memory than specified, but may have problems
if you mix the standard speed and the faster one. There may be other
cases I didn't hear of, too. I recall there was a very strange thing
like that with some of the first TiBooks, where RAM that looked
perfectly OK on paper and that worked in some, didn't work in others.
Evidently there is more to ram chips than we mortals usually see...
I've finally traced the problem. What I did is put my original 512
module in and run the computer from about 9 am until I went home. Then
I swapped it out and replaced it with one of my other modules. The
system froze after about an hour. I then swapped that module out and
put in the third module and the system ran the rest of the evening and
overnight and then went to sleep (at my request) while on the way to
work. It worked fine, so I put back in the module that had crapped out
after an hour. The system froze within 10 minutes. We had used some
end of fiscal year money to buy a 1 gig ram stick (for my powerbook it
was a DDR2 PC-4200 533 bus) chip. We purchased a Corsair Value Select
module since it seemed to satisfy the specs. When I found the problem I
went to Corsair's site to register a complaint and ask to have the
module replaced. I was essentially told that their "value select" ram
didn't work in a powerbook. I should have instead have purchased their
other PC-4200 ram (which was twice as expensive). We are hoping to
return it and exchange it for Transcend memory since that's the kind we
purchased previously and it seemed to work OK. Since we bought it at
Newegg only about a week ago, I'm hoping that they will allow us to
exchange it at no real extra cost.

dick
Jon
2006-05-03 04:10:32 UTC
Permalink
Post by Dick Sidbury
I've finally traced the problem.
Good for you! And I see it was the good old-fashioned tiral-and-error
that did it. Thought it would.
--
/Jon
For mail address, run the following in Terminal:
echo 36199371860304980107073482417748002696458P|dc
Skype: storhaugen
FPP
2006-05-03 07:38:23 UTC
Permalink
Post by Dick Sidbury
Post by Jon
Post by Dick Sidbury
If the intermittent problem does NOT show up, can someone
suggest a way of determining which if either memory chip may be at
fault. Or other suggestions about what else to try and diagnose.
In certain cases it may actually not be either module, but the
combination of modules..
An example is where you have two slightly different ram speeds. Many
machines will accept faster memory than specified, but may have problems
if you mix the standard speed and the faster one. There may be other
cases I didn't hear of, too. I recall there was a very strange thing
like that with some of the first TiBooks, where RAM that looked
perfectly OK on paper and that worked in some, didn't work in others.
Evidently there is more to ram chips than we mortals usually see...
I've finally traced the problem. What I did is put my original 512
module in and run the computer from about 9 am until I went home. Then
I swapped it out and replaced it with one of my other modules. The
system froze after about an hour. I then swapped that module out and
put in the third module and the system ran the rest of the evening and
overnight and then went to sleep (at my request) while on the way to
work. It worked fine, so I put back in the module that had crapped out
after an hour. The system froze within 10 minutes. We had used some
end of fiscal year money to buy a 1 gig ram stick (for my powerbook it
was a DDR2 PC-4200 533 bus) chip. We purchased a Corsair Value Select
module since it seemed to satisfy the specs. When I found the problem I
went to Corsair's site to register a complaint and ask to have the
module replaced. I was essentially told that their "value select" ram
didn't work in a powerbook. I should have instead have purchased their
other PC-4200 ram (which was twice as expensive). We are hoping to
return it and exchange it for Transcend memory since that's the kind we
purchased previously and it seemed to work OK. Since we bought it at
Newegg only about a week ago, I'm hoping that they will allow us to
exchange it at no real extra cost.
dick
Glad things are working out... I'd still encourage you to run memtest,
though.

Especially *after* you get your new RAM.

I ended up going with RAMjet, even though they were a little more
expensive. Figured the extra bucks were worth it to get RAM that was
supposed to be more within Apple's specs.

FPP
--
A pessimist says the glass is half empty.
An optimist says the glass is half full.
An engineer says somebody made the glass
twice as big as it needed to be.
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