The remote can itself be tested and if ruled out the problem can be the remote receiver in the set--a lot of digital cameras when remote pointed at them and button pressed will show a flash on the camera screen in dim light indication if it is working or not.
General information on remotes with problems:
Remote issues and answers:
If you are using a "universal" remote do not expect it to if it evenprograms to have all the functions you need or had with the"original" remote.
If you are searching for codes for a universal to program it: GOOGLE the modelnumber of the remote for "codes" or if you do not have the ownermanual GOOGLE the model number of the remote for "manual".
Some remotes have a search feature that allows you to try all codes on at atime.
Universal remotes are far from UNIVERSAL.
If you have a remote that does not work at all--have it tested first: a remotetester is used at many electronic repair centers and places like Radio Shack
Point remote at the tester and press any button and a strip or light willflash----some digital cameras will also react on display screen to this.
If dead check the battery/s and the connections where they go and if only somebuttons have to be pressed hard the unit may have had something spilled on it:it can be taken apart and cleaned in a proper way to resolve this.
If it has been dropped it can also be taken apart to see if the infrared LED/sat its sending end have come loose from the circuit board inside the remote.
Lastly is the best argument for an original remote is on many sets even if itprograms it will just not have all the needed functions the original one had.
Many companies especially on units with DVD OR VCR built in change the codewith each model and or year as most of these are not actually made by thecompany whose name is on the unit.
Let me know if you have further questions and I will try to help.