A few people have done similar repairs successfully (e.g this one and this guy), but i found this one particularly interesting since it uses a ATMega328 to interface with the Fluke, and I happen to have most of the components laying around.
|Fluke 8050A with a new LED display.|
In short, the 8050A uses multiplexed data from a 3870 microcontroller. The multiplexed data lines are all available on connector J1 on the display board. These are connected to the ATMega, which demultiplexes the data and communicates to a MAX7219 LED driver which again drives six common cathode 7-segment leds. You should read The Belfry blog for instructions on how to do this. I just downloaded his code and did not change anything.
|Breadboarding the circuit connected to the Fluke 8050A|
|The circuit soldered on two stripboards. It is a tight fit.|
So, I now have a 1979 Fluke with fresh batteries and a brand new display which is way better than the original LCD, ready for another 30 years of duty.