I have a 3 car group. Cars 2 & 3 run completely fine, but car 1 is doing all sorts of crazy stuff. It'll work fine for short while (about 5 minutes max), but then my earthquake relay, my fire service relay (PHI) and my switch over relay on my SOM will all pick and drop in no particular order or pattern. Sometimes it will hold the earthquake relay and shutdown on EQO, sometimes it'll shut down on EFOand pick the PHI contactor, and sometimes it'll shutdown on NAV when my SOM relay drops - it's all random. I can sometimes do a 151 and it'll return to service, but then it'll start doing the relay nonsense not long after. I have my 30v all throughout my RSL when this happens. My GL1 LED on my RCB2 board will go out (indicating I lost my RSL) when my SOM drops, which makes sense. I also notice when it shuts down the frequency across my group communication stops fluctuating - I noticed it typically bounces between 3 sets of numbers when running normally, but I can't recall what the Hz are. I've swapped the RCB, SOM, and my C1RS board for fire service with car two to see if i can move the problem, but it did nothing. I've removed RS boards to try and eliminate the problem, but obviously my unit just shuts down on whatever board i remove (ie fire service for C1RS). I'm questioning whether my termination resistor for group network is bad, or CPU is bad, or possibly my MLB, maybe even my chips. To be honest I'm completely lost on what to try next.
I'm headed back there first thing in the morning, but I'm shooting in the dark at this point. Any and all suggestions are immensely appreciated.
Work safe
