[Raion]

So I have an Onyx2 with a DG and IR3. So I have some experience here with these systems.

So first, let's start with physical: the connectors for the DG are delicate, easily bent, and also can get clogged with dust.

Here's how to remove it properly:

Step 1: Make sure you have sufficient space behind the unit. It's a big board. Don't be a dumbass like me.
Step 2: Gently unscrew both sides about 2-3 turns at most. When you feel resistance, grab the pull handles and gently wiggle it out some.
Step 3: Repeat this process, but as you get it started, wiggling should not be necessary and it should just pull straight out.

Ok, so you got the board out, and none of the ASICS are bad, none of the components appear knocked off. Blow out the connectors with compressed air, then turn to the inside of the chassis.

Take a strong flashlight and inspect the connectors for dust, debris, bent pins etc. I've never bent pins, fwiw, so no advice for unbending them.

If you see any dust, you're gonna have to clean the connectors. Take a credit card, wrap it in some sturdy paper, and wet the paper with windex or alcohol. Run it gently through each of the lines, then blow them with compressed air.

Ok, so you cleaned the connectors. Reseating is easyish.

Step 1: Line the board in the tracks in the chassis.
Step 2: slide it in gently, but ensure it's in the tracks, and use your light as a visual guide, pulling nearby boards if necessary to get a good view.
Step 3: Seat it by pressing on the back straight in. I do this with both hands, and a piece of wood to spread the force across it. Once the screws start biting, carefully thread them in (don't cross-thread, I've done it and had to chase the threads. Not fun!!!) and then do the same screw, slide, screw thing. Once the board is almost all the way in, you can safely wiggle it into place if needed, but please try to just press it in.

As for checking if they're running, I don't think SGI released any software to test that sorta thing so you'd need to use a logic probe or scope to find clock signals, and with a chassis like that, it doesn't sound fun.

If you need a DG, I may have a spare socked away somewhere, but you can find them on that one evil auction site that mustn't be named, just go into business and industrial adn throw part numbers in.