[noleex]

Can someone tell me what’s that cable for, just found it soldered on the mainboard ?

[robespierre]

That is what is known in the trade as a "bodge wire". It is a rework to the board usually done at the factory as part of a repair or ECO (engineering change order).
As to its purpose I can only guess, but it does connect near to the Dallas Timekeeper, which as its name implies keeps the system time when power is disconnected, but also holds the boot variables and can power the machine on at a specified time.

[Jacques]

Both my O2 boards have various patch wires, nothing to be alarmed about.

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Someone documented it in this thread:
https://forums.irixnet.org/thread-578.html

That's an excellent guide! Thanks for the link.

I see my photo links have disappeared, I'll try and get them back up.

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"Please excuse the crudity of the model, I didn't have time to built it to scale or to paint it."

I build in some PC Hardware with an Gforce 980GFx to run the Oculus Rift for my kids ;-)

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So for the O2 Problem I‘ll try to replace the CPU unit with another one and have a try, btw I read something about upgrading a R5K to an 10K, I‘m not sure but I have this CPU laying around may somebody can spot it if it’s an O2 R10K cpu ?

Make sure the white pimm connectors are not damaged before you place the pimm on the risers, it looks a bit like you have some damage on the two white riser connectors.

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So with the boot on power plug scenario, the O2 will pretty much cycle like this until a successful boot. This is how both mine boards behave after doing hardware work. Once it boots successfully it *should* return to normal...'should' being the operative word here....

[noleex]

Today I has some time to play around with this o2 issue. The thing is that the power Led is solid red from power on, as I know that means CPU failure, so I swapped the R5k from a fully working O2 to the one with the issue, but it doesn’t chance anything, still solid red light. I also tried the cpu from the not booting o2 in another o2, CPU’s are all working without an issue. Then I tried to replace this risers on the motherboard but with no luck, the box isn’t booting with this mainboard, means the issue is with the mainboard itself and not with the CPU. May anybody has an Idea ?

[weblacky]

So, I'll admit I don't have full knowledge of this entire thread, so sorry if this is a repeat. Power supply? You've tried swapping both CPUs and risers, so it's either Mainboard, Moosehead backplane, or PSU.

I'd try PSU next or at least test it's PSU in something else? Whichever you're comfortable with.

Just a thought.

[noleex]

As I already wrote above, this o2 boots correctly with an other Motherboard Unit, so means it cannot be the PSU or backplane. I don’t know what’s the moosehead, but I guess the issue is the mainboard.

[weblacky]

Moose head backplane. The large board that connects mainboard to drives to PSU. Similar in position to the Xbow on an Octane (central nexus of all modular connections).

[noleex]

Yea got it, but the o2 works fully with a different mainboard unit, so I think that it could not the backplane, also tried to replace all rams, and the pci Modul with no luck.

In fact, o2 doesn’t work with new cpu, with new PCI Modul, with new ram, with new psu

but works with, new mainboard and all stock components of this o2..