Update on the Octane2, short version: it appears to be a problem with the Mainboard and I have decided to donate it to a friend.
Longer version: I have a couple of Octane1's and was concerned about just trying parts swapping, thinking I could do damage to a known working Octane. Weblacky and I were going to do some parts trading anyway, so he offered to help me prior to us exchanging parts. He explained a measurement plan that would reduce the risks and I ended up learning a lot. I unplugged the Cherokee PSUs from both machines and let them sit overnight to be sure they had no juice. With his guidance, I measured the resistance between the pins he specified on the Octane2 PSU to look for a short. We compared my measurements to his, there were some differences but nothing major. Then I measured my other PSU from the known good Octane1 and it was quite similar to the Octane2 PSU.
So I tried the Octane2 PSU in the Octane and it booted up just fine. No issues, great.
Then per Weblackys plan I measured the pins he specified inside the Octane2 itself, he did the same and we compared. Not much difference there either. So without significant anomalies so far I decided to take the possible risk and try the Octane1 System Module in the Octane2. It fired right up, booted normally, no issues.
Then I put the Octane2 System Module in the Octane 1 and no good, same as the Octane2, all 3 fans spin up as soon as the power cord is connected. So per his suggestion I removed and reseated all the RAM, no difference. Then I removed the Octane2 RAM and put good sticks of RAM from the Octane1 and tried again, no difference. Then I removed, used a little canned air on, and replaced the processor. No change, still the fans fire up as soon as the machine is plugged in, no picture, and the lightbar stays completely dark. Then put the known good Octane1 CPU in the Octane2 System Module and tried again. Still no good.
Oh I should also mention, the insides of this machine, and all compression connectors were spotless.
So at this point I decided that I have hit the end of what I have time and energy for, time mainly with ridiculous hours, a family, and learning C. I almost bought another mainboard from eBay, but I decided instead of rebuilding a functional machine, and then having more functional machines than I need, and no spare parts, I will keep its RAM, CPU, Cherokee, etc. as spares for my Octane1's. To each their own right? I do prefer the blue case of the Octane2, so I will put Octane1 internals in it, from an updated Octane1 with plenty of RAM.
Thanks for reading.
KB