Why did you renew batteries?
What type of remote?
supplied with unit or not?
Multi remote purchased seperately?
Check that you have selected correct unit, ie TV DVD sattelite, whatever. check that unit does not need to reprogrammed with the type code, should of been supplied with remote. different units need a type code to tell it what unit it is suppossed to be controlling.
Not enough info to go further
Sheepdog, September 2009