If you've checked the batteries are ok and correctly inserted, other common faults are:
1. Bent, missing or corroded battery terminals - replace terminals or staighten and clean with fine file.
2. Grease or liquid covering pcb carbon contacts - clean with damp cloth & dry immediately.
3. Dry soldered connections to the infrared diode at top of the remote - resolder.
4. Failed connections to crystal - replace crystal or repair lead wires.
5. Fractures to the printed circuit board if it has been dropped - usually not repairable.
If unrepairable...
Philips Universal Remote controls, covering most of their models are widely available from TV/Video suppliers. You shouldn't have any problem locating a replacement and they are generally reasonably priced.
(PS. I advise not posting personal details in online forums.)
Cobweb
January 2005