Short answer: No, not during business hours unless you’re feeling brave.
Long answer: At least with Cisco 3750s, these devices have been notorious in my experience for causing switch(es) attached to reboot when flipped over, despite mains power being fine. They (along with Cisco 3750s) have also had a high failure rate so the sooner you can get rid of them and move to hardware with dual PSUs, the better.
Seeing as the RPSs can only run one switch at a time, it doesn’t make much sense to be cheap and use them as backup for multiple switches.
There is also another major issue with using RPSs: If the switch is running on the RPS DC output, you most likely won’t know if the mains power supply in the switch is OK until you offline the RPS. Not fun if you decide to try this during the day and the switch PSU has blown.
A Cisco ASA5550 was stuck on “Booting system, please wait…” after a power cycle (physically turning off and on, not just a reload). It was impossible to break into ROMMON from here.
After taking the cover off and doing some experimentation, the issue was found to be a faulty DIMM slot. We removed all DIMMs and replaced them one by one. Upon placing a DIMM in slot 1, the firewall failed to boot again. We swapped DIMMs 1 and 2, still no joy.
Removing the DIMM from slot 1 again meant that the firewall came back up.
Solution: If an RMA is going to take time, bring the firewall back up with less memory. Otherwise, swap the thing out straight away as you don’t know what else the power cycle has fried!
You can make your life easier doing the replacement by moving the old ASA’s compact flash card to the external (disk1) slot of the new one. You can then get the right OS on the replacement quickly at least.
NEWASA# copy disk1:/[IOS-image-name.bin] disk0:/[IOS-image-name.bin]
NEWASA# boot system disk0:/[IOS-image-name.bin]
NEWASA# wr mem
Note: you can copy the running-config on the old ASA to a visible file on CF (eg: copy running-config disk0:/myconfig.cfg), but copying that from disk1 to running-config on the replacement tends to not work very well if you have TACACS config in place. Good old copy and paste from a backup is the way forward.