I’ve been following your project, it actually made me consider the Quadra 950 in the first place,
Well I'm both happy and sorry for you! The key (being a car guy), the speed (being my first 040) and the expandability is what drew me to the 950. But it's plagued with reliability problems. Hopefully an ATX PSU will solve most of them. It also can suffer from Maxell explosions, being manufactured during that time frame. Tantalums on the logic board can also go bad and explode...
I also find that it's a shame that Apple didn't upgrade the controller to support SCSI2 fast speeds... Apart from that, it's easily overclockable to 40MHz, it's got great built in video, can have up to 256MB of RAM and has an upgradable ROM (compatible mechanically with that of the SE/30 and I already found a hacked image with a disabled RAM check online!). Mine has 256MB now and it's slow!
And after taking the PSU apart, for a good clean
Oddly enough, I think this can cause more harm than good. But I can't stand bringing home someone else's 30 year old dust so I HAVE to thoroughly clean every thing I buy second hand (mostly Macs).
If I decide to take the ATX path, where do I start? And
@BadGoldEagle how is your project coming along, what’s the latest news?
If you're in a big hurry or if you don't need a working monitor plug, hard drive connectors or a temperature controlled fan, you can go ahead and do
the Geekdot mod. If you want a quick and dirty way to power up your Quadra, you can buy a 24-pin ATX extension cable and rewire it accordingly. You'll lose soft power but it's a great way to check that everything is fine and it's really easy, you just need staples.
I just posted about my mod. It's going along really well but I still have triple check everything before I send you guys kits, so I need a couple more months. I'll also write some instructions and provide a template for the drilling if you want to use the same PSU.
The big issue with the ATX mod is that it's getting really difficult to find modern PSUs that match the original's specs. Depending on what you're going to do with your Quadra, a PSU with a 20/25A 5V rail may be sufficient if you don't chuck it full of hard drives/expansion cards. The Bicker BEA 630 matches almost exactly the original specs and doesn't really need a fan. I also just watched LTT's latest PSU video about the new ATX12VO standard. I hope it won't be universally adopted.