Is your problem with the right channel not working true for all sources or just one?
If it's all sources, then your issue is somewhere with your amp/preamp. LIke if you moved your amp to change speaker cables, maybe your right channel interconnect to your amp from your preamp was pulled loose, assuming they are separates.
If it's one source only, then maybe your interconnect was pulled loose when you were tugging on the speaker cable to change them.
I don't think it is likely that you blew out an amp channel when you changed your speaker cables, but it might be worth checking if the interconnects are OK.