What should I do about Potterton EP2000 programmer?

This has been perfect for the last 19 years. The HW is still perfect. The CH has developed the following faults.
1. Set on "24 hrs" shuts itself down after approx 2 hours.
2. Set on "once" or "twice" will shut off at 11.50 pm but when starting at midnight does not switch off at programmed time.
Is this repairable? Do I need a new one?

Many thanks for your advice.