RB800 + RB816 No traffic on switch ports

I’ve exhumed an old RB800 with its daughter board RB816 running 6.49.18 for lab purposes.
The additional 16 ports of the two IC Plus 178C switch chips are seen
Any port with a connected ethernet cable is marked as Running
But there is no traffic through these ports
Any suggestion other than throw it on the wastebin ?