NetDIMM Option board network issue?

[Butter Meister]

I've received my friend's broken NetDIMM that isn't booting from network with a typical Error 34. Dimm chips and RAM were reported all good. I have my own working duplicate setup to swap parts with. I've narrowed things down to where it's not the Naomi systems. I've tried swapping zero keys, spraying contact cleaner, and replaced the dead large battery pair.

Importantly I've ABBA swapped my NetDIMM's option board with my friend's. Their option board works perfectly on my NetDimm main board. But my option board attempts to boot from network only to hang not doing anything, not even giving up to report an error code. I don't know if this could be a buffer chip issue, as it's not the typical Error 22 seen with that. What other tests can I perform? What voltages should I be looking for? Please tell me more about this buffer chip and if this could help my case.

 

[Butter Meister]

Interesting. I tried my option board on my friend's main board, and it worked. Wanting to rule out things, I tried ABBA swapping the IC, voltage regulator, oscillator for the Fast III chip. The status LED's on friend's option board now indicates the chip is booting, but no physical link is being seen. I was tempted to swap the ethernet connector as well, but that gets continuity over the cable.

 

[Butter Meister]

After trying every component on the dang option board, I have to assume the Fast III chip must be dead. Suspicious AliExpress orders for new old stock is my only option at this point. If it works you'll know