MaxPowr G3 400/200 not working properly in 7500

[cowdog360]

Hello all,

I have a 7200 with a 7500 mobo (rev B ) in it with 256MB RAM.  I just got a MaxPowr G3, and the system runs just fine with the card installed.  However, the backside L2 cache on the card doesn't seem to be working.  I've tried OS 8.1 and 8.6, clean installs.  I've tried the MaxPowr software versions from 1.3 all teh way up to 2.0.5.  The gauge pro works and shows the card, but the L2 is disabled.

When I launch the Maxpowr control panel, it says "The Maxpowr G3 card or software is not installed correctly or is not functioning.  Changes will not take effect."  Any changes I make to enable the L2 fail.  The extension is in the system folder.. at a complete loss.. Tried CUDA reset,, PRAM zap, etc.  It's a very strange one.  The CPU is fast, but obviously without the L2, it's not as fast as it could be.

Any ideas??

 

[Unknown_K]

Did you pull the original CPU cache module off the motherboard? The original CPU on that is a 601-100 and the cache model (offset in between the 8 RAM DIMMs) will not work with a G3 upgrade.

 

[cowdog360]

Did you pull the original CPU cache module off the motherboard? The original CPU on that is a 601-100 and the cache model (offset in between the 8 RAM DIMMs) will not work with a G3 upgrade.

Yeah, makes no difference.  I'm wondering if there's something wrong with the card, or with the motherboard.  A 180mhz 504e and 256mb of external cache work ok though.. It's just like the software can't talk to the card.

 

[Unknown_K]

That would be 604e and 256K cache correct? Which model Maxpower do you have?

 

[cowdog360]

That would be 604e and 256K cache correct? Which model Maxpower do you have?

Correct, 604e and 256K.  Sorry for the typos!

The MaxPowr is a G3 400/200.  

 

[Unknown_K]

Does it have DIP switches?

 

[cowdog360]

Yes, currently all 4 are set to "OFF".  I've tried it with 1 on all off, 2 on all off, and 3 on all off.

 

[Unknown_K]

https://siber-sonic.com/mac/etc/MAXpowrG3manual.pdf

 

[cowdog360]

https://siber-sonic.com/mac/etc/MAXpowrG3manual.pdf

Yeah, I've gone through that one quite a bit.  This is certainly an annoyting one.  I wish I had another mac to test this thing in to see if its my particular motherboard or the card itself.

 

[Unknown_K]

I have a bunch of G3s but they are all Sonnet with no jumpers and they all work (well except for a completely dead 500/1Mb).

 

[trag]

You might remove the heat sink and check the pins of the cache chips for stray heat sink grease.   I had an X100 G3 upgrade once with similar problems.  Enabling the cache crashed the computer.    When I removed hte heat sink and took a look, I found that they had dribbled heat sink grease across the cache chip pins during manufacture.