Author Topic: CPU upgrade problems (OWC Mercury Extreme 1.3Ghz)  (Read 194 times)

Offline Greystash

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CPU upgrade problems (OWC Mercury Extreme 1.3Ghz)
« on: February 15, 2020, 04:28:12 PM »
I recently bought an OWC Mercury Extreme 1.3Ghz upgrade card for my QuickSilver for $30NZD. After installing it Mac OS 9 gives the following error when performing it's boot tests - "The built-in memory test has detected a problem with cache memory. Please contact a service technician for assistance".

After running AHT i get the following error codes:
scc_/3/7
post/16/64

Apparently the scc error is common after installing CPU upgrades (https://discussions.apple.com/thread/2077663). The post error sounds like it's reporting an issue with CPU cache, and would explain why there is no mention of L3 cache in Apple System Profiler. Has anyone experienced this before? Is it safe to clean these components with Isopropyl alcohol and Q-tips? It doesn't look that dirty :-\

Offline FdB

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Re: CPU upgrade problems (OWC Mercury Extreme 1.3Ghz)
« Reply #1 on: February 15, 2020, 05:19:45 PM »
Quick search provides that no firmware update or software enabler for these is necessary?
(Would’ve been my first question.) Seems odd if it does not require such measures.

Did you try “bumping” the CUDA?

Any time a change of this sort is undertaken, seems that a general “self accounting”
by the machine would be necessary? No specific instructions provided with the upgrade?

Might try a desktop rebuild or PRAM zap to see if any difference might then be noted…
before trying the CUDA. Anyone have firsthand experience with this particular upgrade?
AND were there two different versions of these…
one for Quicksilvers and the other for earlier machines?

And ya can always turn off that memory test. ::)

Check and/or replace thermal paste.
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Offline Greystash

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Re: CPU upgrade problems (OWC Mercury Extreme 1.3Ghz)
« Reply #2 on: February 15, 2020, 06:39:01 PM »
Thanks for the reply FdB. I should have mentioned that I had done the following prior to the above testing:

- Press the CUDA button immediately after CPU installation
- Zap PRAM 3 times
- Replaced thermal paste (it was completely dry..)

It appears that the Quicksilver doesn't need a Firmware update, it's stock firmware is above the required version. This upgrade is compatible with all G4 AGP/Digital audio/Gigabit models + QuickSilvers. Mac OS 9.2 is the only requirement for QuickSilvers.
Here's a link to the installation instructions/info: https://eshop.macsales.com/tech_center/manuals/mercuryextreme/OWCME4800L2S.pdf.

I thought about turning off the memory test but It looked as if the machine was being limited with no L3 cache.

Progress
After a lot of mucking around I can get it working on all speeds within the 800Mhz - 1.2Ghz range by adjusting the jumper settings. AHT reports all test pass within this range. Anything from 1.3Ghz - 1.4Ghz results in the same errors and unrecognised L3 Cache.

I'm happy with a 400Mhz increase but it's odd that it won't run correctly at the marketed speeds.