Cotron
Built in the 1970s and used by Yorkshire Television these were acquired by YSTV.
Their robust metal frame and easy access to circuit boards make them very easy to repair, since all of the circuitry uses discrete components (except for a couple of 7400 series logic gates on the pulse cross circuit, which isn't really needed anyway).
Brought back to life in a blitz by Dominic Plunkett, they still find applications despite being only black and white tubes in NaffoCue.
During Dominic's time only one failed beyond economical repair. Dominic's suspension was aroused when on entering the station he could smell burning electronics. His pace quickened slightly and spotted smoke coming out of one of the monitors in the monitor rack. At the same time a comp sci said "Dominic there is smoke coming out of one the monitor" before he'd finished the sentence the power to the station was off.