>The team discovered that a single chip responsible for storing a portion of the FDS memory — including some of the FDS computer’s software code — isn’t working.
No one thought of having backup computers on the spacecraft?
Most of the computer hardware is duplicated but much of it has already failed/failed earlier - remember these are 50 year old hardware - a lot of the logic is TTL and discrete components - which are far larger than modern equivalents would be.
It's not just 50-year-old hardware: it's hardware that's been subjected to cosmic radiation for 50 years, part of that outside the solar system (so presumably even higher).
No one thought of having backup computers on the spacecraft?