Hello,
 
I've a problem with one of my track circuits:
It's a very simply circuit, divided in four blocks. It was running the past 4 years without any issue. Suddenly the block control doesn't work anymore in block one. The trains are running through the whole circuit but stop in block one.
 
I removed all the trains and measured the voltages, there is about 12 V in all blocks. When I put one locomotive in the faulty block, the voltage in this block drops to zero, the loco is not running. It looks to me as if the block control of block one would set the status for the block itself to "blocked", so it cuts off the power.
 
I've exchanged the module (SSS?) as well as the one of the block before and the one after, checked all the connections twice and measured whatever was measurable - no success.
 
Long story short: Does anyone have any idea what went wrong here, how to fix this or something else I can try?
As mentioned, it was running for years, then without any changes suddenly not anymore.
 
I have no idea how to continue here...   
 
Thank you very much for any help or hint or solution! 
 
Frank