Problem with S-10 Remote

I use an S-10 remote to simultaneously power a TV, AT&T U-verse DVR and a Pioneer receiver, to which are connected five speakers. The remote performed reliably until a power failure a while ago. Since that time, the S-10 remote will not consistently turn on the sound on the receiver, even though the receiver lights up as though it should operate (it turns everything else on.) If I turn everything off and power up the remote again, the sound will usually go on. Sometimes, however, I have to manually turn the receiver off and on to get the sound to work. I cannot tell whether the problem is with the receiver of the remote. Can anyone suggest a way to troubleshoot? Would re-programming the remote be on any value?