That looks like it could be a split-bobbin isolation transformer. 220V in, isolated 220V out, and its only good for max 136mA. It also looks like its overheated enough to partially melt and distort its bobbin, which, if its load is some sort of wide input range switched mode PSU, could be due to running it on 115V which would double the current. A loose connection to your step-up transformer, disabling its boost, could also be the cause