Power Macintosh 6500 Sonnet G3 L2 Crashes During Boot

[willmurray461]

I'm currently trying to boost my Power Macintosh 6500 with a Sonnet L2 G3 upgrade, but I can't seem to get any of my *three* units to work. They all crash the computer right before the extension tries to load. I tried both the 2.3.1 and 3.1 driver, and neither work for me.

I followed the Sonnet manual and installed a "Universal" copy of 9.1, so I don't think software is the issue.

Does anyone have experience with these cards? Is there a chance all three failed? I read somewhere that the cache chips on these die and/or the CPUs may overheat. Should I try replacing the cache chips or CPU?

 

[ObeyDaleks]

I have one of those and it never caused a crash. Are you sure it's crashing? If I remember correctly, the Sonnet pauses for a bit (like 30+ seconds), while switching to the cache card CPU.

 

[willmurray461]

I get to the progress bar, then after about 20 seconds the mouse locks up and the whole system stops responding.

 

[ObeyDaleks]

Hmm did you try zapping your PRAM?

 

[Byrd]

Sonnet accelerator cards were pretty pedestrian in the day, they sold well and are sought after upgrades now as they still work. I can confirm that other more bleeding edge upgrades do have issues with faulty cache and/or need to be derated in speed to function reliably.

It's unusual then that you have 3 x Sonnet L2 G3 cards that appear faulty. The purple heatsink on the L2 G3 cards can flex the card, so check this and replace thermal paste on the way be careful to tighten all screws progressively to avoid flex. And do the usual things like clean the L2 slot, check PSU voltages, reset PRAM and CUDA switch on the 6500 motherboard.

There is also a utility called Sonnet Clocker II that lets you adjust multiplier speeds, I've not tried under clocking but also worth a shot

The 6400 Zone - Sonnet Clocker Info

 

[willmurray461]

Yes, I tried resetting the PRAM (with CMD-Option-P-R), as well as the CUDA switch.

I re-pasted my cards and made sure to not overtighten them. However, I did accidentally over-tighten one card in the past, and now I'm afraid I ripped some pads underneath the BGA or something.

I'm beginning to suspect something is up with my motherboard.

I did notice, however, that two of my three cards are factory overclocked (a 400MHz unit with a 350MHz CPU, and a 500MHz unit with a 400MHz CPU). I wonder if this has anything to do with the problems I'm encountering. Cache chips are the correct speed though.

I have a spare set of cache chips from a donor PMG4 CPU card, as well as some NOS PPC750's that I could swap in, but before I do anything that extreme, I think I should probably buy another 6500 logic board just to make sure it's not the board.

I might also give under-clocking a try, as that sounds somewhat promising.

 

[willmurray461]

I found out the issue! I neglected to mention that my 6500 motherboard was being used in a "TAKKY" Color Classic. I forgot to connect the 3.3V rail to my PSU, which was preventing the G3 L2 upgrade from getting any power.

I was totally overthinking things! All three of my cards work just fine.

 

[Byrd]

Glad its working, interested how you go with your G3 Takky, I've one recently rebuilt and it certainly pushes the limit in terms of power draw and cooling, working well now though.

 

[willmurray461]

I'm using an ATX PSU with Pizzigri's custom analog board, so I doubt power will ever be an issue. Cooling may become a problem at one point, though adding a fan shouldn't be too difficult if necessary.