For those that don’t know, when I say “stack”, I mean a group of 3750s connected together using the StackWise technology. When you use a very expensive and very proprietary cable, your individual switches are combined into a single logical device. This means you configure one device to control potentially many switches.
To the point. I’ve spent the last few weeks replacing a mess of 3750s in stacks. These guys are very easy to replace, but the big problem I find is getting the IOS version in sync. When the RMA comes, it’s inevitably got a different version on it, and you’ll see something like this.