Fitting the PS1201C01 into the C90
The original power supply on C90 series is a Honeywell product. The PS1201C01 power supply board board edges needs to be trimmed in order for it to fit inside the C90 power supply cavity.
On previous generations Honeywell used to mark the edges to indicate where to trim. See photos of previous generation marks and edges. This can be easily done with a file.