BA11 power filter

After a few years in storage I'm finally getting to play with my PDP-11 stuff again. Figured I'd start small so rolled out the 11/23. PSU looks fine, pulled all the cards and checked voltages, no problem. Shortly after however, some magic smoke was released from the block in the back where AC comes in and the power switch is mounted. The only other thing in there is a big old line filter. Judging by the smell, I suspect a filter capacitor has given up the ghost. I'd check, but the whole thing is soldered shut so not exactly easily serviceable. Would I be correct in thinking such filters aren't entirely necessary and could just be bypassed? It looks like the manufacturer (JMK) is still going so a new replacement might not be out of the question. Whether I could find one with the same mounting holes etc. is another question I've not looked into yet. Cheers, Steve