Thunderbolt display flickering then black

I have recently managed to connect my c. 2012 Thunderbolt display, with 'hydra' connectors (power and data) to a newer (2019) MacBook Pro via a Thunderbolt 3 to Thunderbolt 2 adapter, which worked fine for a few weeks, but has now started to have the Thunderbolt display flickering madly, then losing signal and going black. I was tempted to think that this was a dodgy connection somewhere, and it is easily remedied by disconnecting and then reconnecting the adapter, but only for a matter of 30 seconds or so, before the mad flickering and cutting to black happens again. So I don't think it is a dodgy connection.

Any suggestions? I am loathe to get rid of the display, which is more than 10 years old, but in mint condition (other than the flickering and dying....)