I have 4 dead circuits which were intermittent off/on at first- now dead. The 20 amp dual tandem breakers are across from each other in the breaker box. The breakers/circuits above and below the affected breakers are live and functioning properly.
There was enough voltage earlier to energize the digital temperature readout on an LG window unit, but turning on a light killed the display.There was also a faint odor of something burning, resembling burnt newspaper. Box and breakers are cutler/hammer.
I'm about to pull the guilty breakers and replace them and check the BUS.