TAC 50-04 Hall Call Issue

Have a 2-car group of TAC50-04's in a hospital that were up and running fine. Now neither car will acknowledge Down Hall calls only.
Cars do have Security and Code Blue, but everything seems normal with the CLO's. DHNF & DCN all show normal. Tried to power off Car 1 with Car 2 running no difference. Tried the same with powering Car 2 off and Car 1 running no difference. Tried to do a TECC with no change. Not aware of any setting, feature, etc that will prevent Down Hall Calls from being answered.

Do the down calls latch but no car answers them? Or do they just light when you push the button, then drop out.

It is possible but not likely that all down calls are secured with SHL command. The SFA command will show any secured floors. DSF will display if anything is secured through IMS, DSFC will clear those.

Check the SCA and SCB scan tables. If the floors have a value of 1, the car would accept only up hall calls for that floor. Don’t know why something like this would Chang though. Are these 16 or 32 bit controllers? I have seen the 16 bit CPUs start to do strange things. Is it a new install with HN cards or. MOD with CNAs?

The down calls light but don't latch.

it is also 32-bit and is not a mod. Has HN's

it is also 32-bit and is not a mod. Has HN's

It doesn't appear to be SCA or SCB or any other setting so far.

Try and reload the group I/O through IMS. I once had a job that the config got corrupted on. In my case it was up calls, my U1 and U2 were flat out gone from the profile. Reloaded .cfg and all ran fine, but I never had a reason for why it happened. If everything is there, try injecting the call and see if the car responds, can also check the hall station and see its lit up to "prove" communication to the station, and that the CPUA still is capable of taking the command.

Edit: forgot to remind you to check OHMs over the HC. 60 is the key, and on groups there where plenty of mistakes turned over. Header jumper on the master car should be removed. When you don't have 60 the communications get really strange.