we have an SLC 5/05 Rack Hard faulting erratically. sometimes on the week sometimes it takes a month.

we have changed the Processor to a new 5/05. i do believe there could be a back-plane issue with the rack. anyone else seen this and maybe what they did to resolve this?

there are no brownouts to speak of to cause this. i was also thinking that a Low voltage +24 V Analog card voltage could cause this as well.

so many variables in the equation, any help or idea would be great....

 

As often not mysterious faults on SLC racks turn out to be power supply problems. What fault code is being generated?

 

Look hard at the power supply as well. I would set up a DSO on this to save time. Switchers have a habit of limping along and occasionally deciding to take a break.

Also cycle all the connectors and tighten all the connections and check the temperature. Intermittents can drive you crazy, and it's usually a Duh! moment when and if you find it.

Believe it or not, I chased one down to an intermittent fuse. It would open for a few moments every other day or not and check fine the rest of the time. Temperature rise thing.

Regards
cww