Classic Mac Hardware (Troubleshooting, Upgrading, & Modifying) > Mac CPU Upgrades

Frontal Lobotomy with SPD error

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FBz:
By all means check the 4th screw (tight - good ground)
and for bent pins. And look for dust, etc. in the pin connections.

And... processor cleaned and fresh heatsink paste applied?



MelTupper:
Okay... Lots of revelations here, but I will try to keep this brief. Installed all new RAM, 3 identical sticks. Ran DIMM First Aid again, and the 'SPD data revision error' has cleared. New RAM checks out perfect. Which makes sense because the SPD chips went away when I removed the old RAM. Yet, the startup error persists: "The built in memory test has detected a problem with the cache memory." This was confounding because the startup memory test is set to "off" in the memory control panel. Compared the Boot ROM versions of both daughterboards, and they match (4.3.3f2). Did a CUDA reset. No luck. Reset the logic board board by unplugging power; removing clock battery; waited 20 min; replaced battery. No luck. Printed out system report in Leopard (10.5.8 installed on a separate hard drive) and under 'diagnostics' it tells me the Power On Self-Test (POST) failed, and the failure type is External Cache. Also in the Hardware Overview section the L3 Cache is made obvious by its own absence. It is supposed to show 2Mb of level 3 backside cache for this particular daughterboard/criminal brain. Okay... Frankenmac people, this is your moment! I did a bunch of reading today, and learned that the L3 chips can and do fail. But, there have been many successful similar lobotomies performed over the years too. There are ways to re-enable the L3 cache. One guy on a forum mentioned that he "was able to revive it with a small voltage bump." Wow! This is all getting very Shelley-esq... anybody know how to do a voltage bump or otherwise enable the L3 cache? Please don't tell me to climb to the top of a high tower and install a lightening rod.

FBz:
Also after extensive searching here concerning this L3 malady, seems I’ve drawn a blank as well. Other than that one reference concerning the reported successful voltage jolt on an MDD.

Any other L3 Zappers here? “Speak up now or forever hold yer…”

But perhaps before you charge up the defribillator paddles, there is this - concerning the good ol’ leavin’ it alone approach (and trying it again, later). https://discussions.apple.com/thread/2629516

“Well after reading your post and the subsequent replies I thought, hmmm, maybe it was a connection problem.
So I put my old DP 800 MHz card into the purchased machine and it started up and ran just fine.
Checking the Apple System Profiler I find the L3 Cache is there too!”

Might be interesting to also try yours, back in the original machine you bought for parts?
I still wonder about all of those little pins…

Some burn sage, or chant ancient Woz incantations. Others, simply wield hammers. But if you’ve considered these last-ditch approaches (and still maybe have some hair left)… I can offer you a tried, tested and true… 1GHz DP CPU (820-1324-A) in exchange for your Regan MacNeil model.



https://www.timeanddate.com/moon/phases/

Lemme know. ;)

MelTupper:
Let me ask you this.... do you think that my old power supply might be too weak, and that the weakness of it might make the machine unable to recognize the L3 cache? I recently also added a Ti4600 graphics card, with (of course) its own cooling fan. Maybe between that and the dual processors there is just too much of a power drain. Appreciate your advice!

MelTupper:
Installed CPU Director in OS 9.2.2. (see attached). Also installed in 10.2.8 (see next post). Hope this info is useful in telling me what the heck the problem is and what I need to do. I was hoping that I would see the option to turn on the backside cache (L3 cache). Under the L tab the radio button for 'on' is selected, but also grayed-out... whatever that means. Enable cache is also selected but grayed out. Still looking for a way to tell my new dual CPUs to activate the L3 cache.

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