I have repaired a quite a few faulty remote controls and most often they are repairable.
Getting a programmable remote is one way to solve the problem but the functionality and locations of the keys may not be satisfactory.
Repairing your remote should give you more satisfaction as you get to keep the remote you are used to.
Common faults are: some buttons not working, not working at all, corroded battery terminals. Often buttons are sticky because of some dirt accumulated over the years from the sticky little hands of your kids?
The hardest part of repair is often to open the covers. You do not need much experience in electronics repair to repair a remote. Also it is perfectly safe as there is no way to get an electric shock as they work with batteries.
Step 1: Test your remote with Digital Camera
Check your batteries first or buy new batteries. Once you have good batteries, you can test with a digital camera by pushing the buttons and having camera on and pointing to the infrared led. You should see red light if the remote is working. If no light comes up you obviously have a dead remote but do not despair and procede to the next step
Step 2: Open the remote control but there is a catch or a few catches.
Remove the screws if any. Sometimes screws may be hidden under a sticker or rubber feet. Often there are no screws at all but just plastic catches hidden so you have to be clever to open it without breaking the case. Use something blunt and flat toclick the covers open. This is often a challenge but should not be too difficult.
Step 3: Take a picture of every phase so you remember how to re-assemble
Since you are using a digital camera you might as well take pictures of the disassembly so re-assemly will be easier.
Step 4: Pull everything apart
Did you take a picture of the keyppad layout? Sometimes keypad is just one rubber membrane but sometimes the keys fall away like pieces of a Lego puzzle. And if the buttons are marked with numbers and functions you may struggle to re-assemble them in right order?
Use a small plastic takeaway box or similar to store the bits so you don't lose parts.