L3 Cache broken?

[iRolleder]

Hey Community,

since a few month I own a PowerBook G4 867MHz A1025. I mentioned an error in the diagnostics tab of the POST. The error says: external Cache. Under the Hardware Tab only the L2 (256k) Cache is listed. So is there a possibity to fix something or is the only way to solve that problem to change the logic board?

The Powerbook still works, the Fan makes some noise and I think ist is a bit slow. The AHT has no problems detected with the other Hardware but it also gives an error (POST/16/64)

Edit: I also tried to reset the SMC and the NVRAM and I have deleted the Cache files. Didn't work.

Edit 2: I am a bit confused, is there a Level 3 Cache? I am sure it should be there (everymac says 1mb is the size of it) My MBP2010 showes no L3 Cache, too... But whats the reason for the failure?

[iRolleder]

Hey,

because there was not much time in the last months, I couldn't solve my problem with the Ti Book. Now I figured out that the MBP 2010 don't has L3 Cache. But the PowerBook should have 1MB and it should be shown in the system Profiler.

See here: http://a248.e.akamai.net/7/248/51/3030351139042133/www.info.apple.com/images/kbase/303035/303035_1.jpg

Some picture of the SP on my PB you can find in the attachment.

So for that reason I ordered a used logic board in the US on powerbookmedic.com (26$ for shipping to Germany  ). When I get it I try to replace it and hopefully the Problem is solved and the Powerbook runs faster again

best regards
iRolleder

[IIO]

guten morgen,

most likely it was broken.

users of third party CPU upgrade might know situations wher you can turn the caches off, but with apple boards this is not the case (to my knowledge), so it cant be that it happened accidentially or so.

[iRolleder]

Hallo IIO,

i found that the CHUD tools may could help me get some details about the CPU. With Hardware Preferences you can get things like CPU speed... In the Internet there was a list with more commands then you get it from the help file. But

#hwprefs cpu_l3_cache=true

results only in the answer: illegal action
The same thing for the L2 cache. That looks like it can't be enabled/disabled by the user, i think.
With OpenFirmware (cmd+alt+o+f) and the command

dev / ls

there comes a list with installed hardware. On top of the list after the cpu there is the L2 cache listed, but not the L3 cache or the L1 cache?!

 

[Knezzen]

I had this exact issue with my old PowerBook G4 Titanium. I figured it was just some bad solders for the L3 cache, but never gave any more thought to it. This was a 867mhz unit just like yours. I think I still have it somewhere, so I could investigate the hardware further.

I have the 1ghz model now and havent had any issues (so far) even when getting daily usage for the past 3 years or so.

[iRolleder]

I had this exact issue with my old PowerBook G4 Titanium. I figured it was just some bad solders for the L3 cache, but never gave any more thought to it. This was a 867mhz unit just like yours. I think I still have it somewhere, so I could investigate the hardware further.

I have the 1ghz model now and havent had any issues (so far) even when getting daily usage for the past 3 years or so.

Thats a good point... maybe its possible to "heal" it in the oven?

[iRolleder]

Hey everyone,

I gave it a try. So first I used a very hot air blower (this things that look like a hairdryer but much hotter) and try to get a temperature on top of the chip (wich I think its the Cache) of about 150°C. This was for about 5 minutes. Afterwards I put it into the preheated oven for about 15 Minutes at again 150°C. The logicboard still works, but the cache is still not working. Maybe it was not hot/long enough to melt the soldering again or its another kind of problem.

Maybe I will try it again until the new/old logicboard is coming...

Best regards
iRolleder

PS: I would have used the modification function but I think after a specific time it disappears for the posts?

[geforceg4]

lol
have any of u geniuses ever considered that some functionality + tampering would not have been dissallowed/disabled access by apple?

[Knezzen]

Nice condescending post there, Chris. Can you post something constructive instead?

[geforceg4]

<post retracted>

[iRolleder]

It's awesome     i got the Logic Board yesterday. After I replaced the old one, the L3 Cache is mentioned again in the system profiler. I didn't check the diagnostic page yet and i haven't tryed to play a video (until now it wasn't possible without adjust the video with mplayer) but it feels much faster now. When I am at home again tomorow I will edit this post and add pictures of the results

Thanks for your helpfull comments