Fault on 1746 L551C

Happy Friday everyone!

I recently installed a new module, 1746 NIO4I, into the last slot on this chassis. Got the normal IO mismatch fault, added the module via "Read IO", saved the configuration, downloaded it to the processor, switched back to run mode, everything ran fine overnight. Today, I went to plug the terminal block into the card, and got faults. I've attached the two faults, and have since gotten them cleared by use of "Clear Faults" a few times. Just wondering if anyone else had issues like this? Possibly defective board? It was in a "Factory Sealed" box, looked to be authentic AB.

Did you insert the module with the backplane powered up ? That could have damaged it all by itself.

I would do a cleanup of the backplane and the module connectors with canned air and isopropyl alcohol to start. There almost certainly is no software or firmware workaround.

I defnitely did NOT insert the module with the power on. I am very aware SLC cards are not hot swappable, we also have ControlLogix racks here, which I have hotswapped just fine, but I still prefer to do them dead, too.

You mention cleaning the backplane, I wonder if it's possible some debris got in there while installing. I am usually very careful with these cards, even wearing the anti-static wrist band. I was concerned primarily because the module had already been installed for over 24 hrs and no faults (other than the initial IO mismatch, which was fixed easily). I only got this error when I went to plug the terminal block into the card. I understood the terminal block to be OK to "hot swap" but not the module.

Thanks for those details ! I agree that you've probably done everything correctly.

Can you put a scope on the DC power and DC common on the analog wiring ? A very noisy signal can bleed over and interfere with the backplane chip interface sometimes, which leads to the "stuck runtime" and "wrong ID" faults.

You have two modules of the same sort, correct ? I suppose swapping their positions will provide a datapoint about whether the problem is the module itself, or the slot or wiring.

I don't have a scope. I do have two of the same cards side by side, as well as a spare of it. If I get a chance to power down the rack for cleaning, I can try swapping cards in the slots. Would a wiring fault cause similar errors? I triple checked my wiring before plugging the terminal block in, so I really don't think there's any problems. I wonder if I didn't just push a bit hard and temporarily unseated the card from the back plane. It is the farthest card out, so maybe a small flexing opened a contact briefly. I'll try not to lose too much sleep over this one!

just some ideas.

does the rack size match in the config table to what is actually there?
is the power supply big enough for the new card?
will the plc support the new card / revision?
power down the plc, reseat all cards 2 times, then remove the power supply and reseat it 2 times also. i has solved the same issue.
hope this helps
james