I have a simplex 2001 panel.
I have almost 12 zone cards and signal cards with 24 different zones.
I faced a problem that some of signal cards are receiving the signal after the alarm and ringing their respective bells but some cards are not. Like I had a spare point and I connected my Bell to that point but the bell only rang once and after that it started to behave the same way as stuck on -16V. Some of the cards are stuck at -16V even after the alarm. What might be the actual problem in my panel as I learned that these panels use jumpers on the motherboard to operate properly.
My only guess is that the panel has some of its jumper wires configured incorrectly (though I would have no idea about how to configure them properly).
We need to know the model number of the panel to properly assist you. It could be the expanded re-packaged model (which only has 2 rows of 8 cards in an enclosure) or an 8001 variant which can go up to 6 rows of 8 cards per cabinet. That will determine the troubleshooting path you will need to take as those two panels are designed essentially nothing alike.
One thing that is universally shared across all 2001s is that most configuration options and logic for operation is wired by hand with jumper wires. If cards were removed from the panel and put back at any time, and that process was done improperly (and a card ended up in the wrong location), that can cause this issue.
Another cause may be a faulty Fire/Trouble Control module or a faulty signal card. You can test the latter by swapping known-working signal cards with ones that are not working, assuming they do not have differing board revisions or hardware configurations (often set with physically cutting parts and/or modifications to the PCBoard). Do not remove or add cards to the backplanes while the panel is fed by AC or battery power. You should completely power down the entire panel and allow the capacitors to discharge (usually takes less than a minute) before making modifications of any sort.