Help with Simplex 2001 Panel

I have this Simplex 2001 panel with the trouble light on. There are 32 zone cards, all of which are fine, no troubles. There are no troubles on the NACs.

Any idea on what could be causing the trouble?

Do you have batteries? That could be the trouble

Is this system in service or in your collection? Which trouble light is on? (SYS, EARTH, or ANNUN)

If the SYS trouble light is on, it could be the batteries or an improper motherboard configuration. Have you moved any cards around?

The batteries are new and pass. The system trouble light is on. Any more ideas?

And yes, the panel is in service, I’m troubleshooting it.

Because 2001 systems are over 30 years old and use early solid-state technology, it’s possible that the system is beginning to fail. The control card might need to be replaced.

Each card slot on the 2001 has several solder points around it that are used as jumpers between cards for custom configurations. If cards are removed or rearranged but the jumpers are left in place, this may cause issues. Many 2001’s were set up with labels on the chassis that show what card belongs in each slot, so it may be worth double-checking. When did the trouble begin, and is it possible that someone messed with the cards before you began troubleshooting it?

Are you a licensed technician or part of the building staff?