Originally posted by: rayvd

Greetings.

We have an FC 5877 hanging off a P750. The 5877 recently went down during power work in the datacenter in which it resides. Our understanding is that the 5877 was split between two circuits -- one of which was not impacted by the power work, and as such, the 5877 theoretically should have stayed up.

One of the power supplies apparently failed at some point during the maintenance work (presumably the one on the active circuit) and the 5877 went down. However, when power was returned to the other PSU (presumably till working), the 5877 did not power on. An IBM FE eventually was dispatched and he replaced the one failed PSU along with the "good" one (to ensure FW versions matched). At that point the 5877 came back online.

I'm trying to understand why the one good PSU wasn't sufficient to power up the 5877. The manual states that the 5877 will auto shut down after 5 minutes if only one PSU is physically installed, but presumably this is for airflow / cooling reasons and wouldn't be the case with a "failed" PSU.

However, I'm not sure what the unit's evaluation of its PSU situation would be if it lost power completely and then came back with only one good PSU -- should it have powered up?

Thanks,
Ray
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Originally posted by: rayvd

It turns out that after further investigation, one of the two PSU's was already failed. When power was dropped to the other remaining, working PSU, the 5877 went down. Once power was restored the unit likely came back online, but due to the F/W revision on our P750 it wasn't able to be properly initialized until the failed PSU on the 5877 was replaced.
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