I don't think I need a scan after all, so please do not disturb what has been working for years.I'll get shots of the 466/1M card up ASAP. How hard is it to removerthe heat sink? I'd rather leave it alone, it has been running
flawlessly for over ten years. [] ]'>
The PPC750 is told the L2 cache size by software (or perhaps it detects it), but in any case, there is no pin which indicates the size. So there couldn't be a resistor on a pin to the PPC750 which needs changing. The only difference between the pinout of the larger and smaller L2 cache chips is one address line. So I guess there could be a resistor in the center of those two (one per two chips) address lines. But I think it would be unnecessary.
One last possibility is that Sonnet uses a resistor to tell some register on the card the L2 size and the software reads that register before configuring the L2Cache Register in the PPC750. But why do that when they can just program the Flash/EEPROM on the card as needed? Of course, I'm assuming there's a flash on there somewhere. I didn't actually look for one.
But, to answer your question, there are four screws which go through the PCB and thread into the heat sink. They can be a little hard to turn, so it's good to use the proper size screwdriver on them. There are also (on this model) little white plastic spacers around the screws between the PCB and the heat sink. So, after extracting the screws, be careful not to lose the spacers. They're easy to overlook.
The tricky part is getting the thing back together. I held the circuit board so that its long edge was vertical (parallel to the direction of gravity) and inserted one screw at a time, putting the spacer on each screw before moving on to the next. Then using my three arms, I brought the heat sink up and barely threaded one screw. Then another, etc. There's a lot of abitility to move the heat sink around when the screws are loosely threaded. I was even able to push the heat sink out of the way enough to get the spacer back on the fourth screw after two of them were already threaded.
I think I actually held the PCB and the heat sink in one hand while turning the screw driver with the other, but it felt like I needed three hands...
Anyway, if you want to make a scan, that would be great, but I think the most prudent course, would be for me to try replacing the memory chips and do some testing. And then, if I can't get the extra memory recognized, I'll go looking for a scan.