> I can see the BTS attempting to connect to the BSC, but after the "Set > Radio Carrier Attributes" request from the BSC, the BTS sends a NACK > and the OML link is dropped.
I think this might be misleading. This post https://www.mail-archive.com/openbsc@lists.osmocom.org/msg10239.html inspired me to use an SDR to check for BTS activity and sure enough it does briefly transmit and then stop. The Telnet log shows "TRX is not responding - reinitialising the unit..." and it looks like the BTS reboots shortly after. I swapped out the 1800MHz BTS for an 850MHz version and had the same behaviour. To rule out a PoE problem I swapped out the genuine ip.access injector for another known good PoE source but the issue remained. I did see the photos on the Wiki ofa NanoBTS with bad caps. Is that a known issue? Visually the capacitors look fine in both units. Unfortunately the 1800MHz model has some quite serious corrosion inside and looks like some compartments have been flooded with sea water or something caustic. The PCB is in reasonable condition but some vias are damaged - it might be beyond repair. Unless anyone has some inspiration I don't think it's worth digging too deeply into the Osmocom side as it's likely hardware issues. Thanks Matthew / marrold
