SLC 501 Problem Fixed

Greetings All,
Just wanted to share a little adventure I has last evening. A facility that we are leasing calls and has a problem with a piece of equipment. All I am aware of is they are running a SLC 501 and the processor is faulted, they can't connect to it with a laptop and their DTAM just tells them the CPU is faulted. I grab a couple spare 501's and make the two hour trip to the other facility. Upon arriving I find that yes the CPU is faulted, there is no battery in place and they have a PIC module that may or may not work. After several futile attempts to connect with the PIC module on their system, I try mine to no avail. After intense consultation with myself I then think, "I hope there is an EPROM on their CPU!" I cut power, pull the faulted unit and sure enough there was. I pulled the PROM and placed it in one of the spare I brought, slapped it in, powered it up and like magic the CPU went into run mode. I then also placed a new battery in the system and test ran the equipment to make sure it was all functional.
The lesson here is to perform regular PM on your PLC's just as well as everything else. Once in a while, just connect your laptop to the PLC to make sure equipment you have is indeed functional so, hopefully, when you need it it's there. Also I can't emphasize how important proper training is.

I say lesson number 1 is to always have backups on file on all PLCs and HMIs. If you had a backup, it would not have been such a gamble to exchange the CPU.

The electrician at this facility did have the program backed up on his laptop, but it did little good since they effectively have no way to connect to the PLC, and I don't have anything as old as a 501, so I didn't have anything to connect to it either. (But I did make a purchase this morning for a 1747-UIC!)

Well that would be lesson no 2.