I had this same thing. All I did was go through my hall LON channel and disconnect and reconnect all my LON connections, then reset. Maybe I just got lucky though. Good luck.

One of my hall station cards is not lit green n may b bad. R these boards drop in replacements with out any programming?

I lost all the hall calls and found a blown F2 pico fuse on a small board around hatch center. It was a small green pico.

Hal station boards are drop in, nothing special, L24 card I believe. LN card is in the hoistway. We used to put them mid hatch a lot, blown picos were very common.

Find the LN card, it's either in the hoistway or in the controller. It will have CAT5 in and out. Check pico fuses and look for a slow steady flash rate. If it's flashing fast, there is an SPI loop problem but that should give you a fault. The SPI loop runs from the out jack on that LN card, in then out of every L24 card in every hall fixture (buttons and gongs, not PI) then it comes back to the IN on the LN card. A problem with any of these boards or cables can cause a problem or open the SPI loop. The L24 cards in the fixtures are plug and play, the LN card is not! Do not swap it with another one or install a new one without loading a LON config into it.

IDWT, did you guys install the LN cards in controllers? Our area, we always did them in the hoistway to TRY and help good signal strength. Mid hatch was the standard to keep any single leg of the SPI loop from being very long. The communication came back directly from the LN card, wondering if it was a waste of time, or if you found controller mounted cards more problematic?

Ok thanks guys. I will b back there Monday morning and I will find LN card. Does each floor have its own pico fuse?

When I was in construction we put them In the controller, even remote machine rooms. It wasn't until I went to service that I saw LN cards in the hoistway. It looks like they did that in the beginning but I don't know when they decided they didn't have to. They are sure a lot easier to work on in the controller!

The pico fuses are only on the LN card, you should only have one. For troubleshooting purposes you can use a good L24 card from the car to try to get your SPI loop up. SPI loop problems can be a pain. You really need spare L24 cards and a good CAT5 tester to find cable/plug problems. But with SPI loop problems you usually have some lanterns and buttons lit and I think you said you had no faults so I'm thinking the pico for fixture power on the LN card.

All of my buttons and lanterns Are dead. No lights But 2 of my 3 hall station cards have a geeen light So Im goin to replace the one that is not lit ..but I have yet to check the LN card. Are the pico's replaceable or would the board have to be replaced ?

Ya they are replaceable

If the LN card has a steady heartbeat it's probably ok. Rapid rate indicates LON trouble....somewhere.
The L24 cards are easily replaced.
On a side note, there have been times I've checked Fire recall only to find after switching back to "off", the hall calls didn't come back on. Turning the fire service key to on/off or bypass restored hall risers. This is on earlier TAC20's with the 2389 keys.

Fire service resets have been notorious for being slow. Even on our TAC 32 units I teach customers to turn to reset, count to 5, then turn to off. Quickly turning key can sometimes reset car or group only, and leads to a lot of headaches.

IDWT, thanks for the info. For sure a lot easier to work on in a controller. I used to keep no fewer than 8 known good L24 cards and cords so I could build false riser in the machine room. With a new LN card you could find and bind, download the Lon.cfg, and trouble shoot bad L24s.

Will a bad L24 card cause rapid flashing light on LN board ?

Yes