So, we have established that your dimmers are ETA and that the
protocol that you are using right now is Ultraplex.
These dimmers are easily 25 years old and likely don't have much life left in them without repairs. Also, you actually haven't given a reason for replacing the board. Are you sure the problems are in the board and not in the dimmers?
As mentioned above, if you want to continue using the dimmers as is, you will need an Ultraplex to
DMX convertor. Don't worry about the
power to the
console issue. Ultraplex was a
protocol that carried control
power along with the signal. Any
DMX board that you acquire these days will have its own
power supply.
Now, finding a convertor that will work with these dimmers may be a
bit elusive. If indeed a converter that produces NSI/
Leprecon Microplex will work, they are kind of spendy. The Doug Fleener converter is over $700 and the Pathway Ultimate Converter is going to set you back at least $1000 if you buy it new. Then you still need a
DMX console. On that front you can spend anywhere from $50 for a used DJ model on Ebay to over $1000 for a new
Leprecon, NSI, or
ETC low-end
DMX board.
Honestly, there is no cheap or easy fix for this issue unless you can find an inexpensive used board that outputs an Ultraplex compatible signal. You're in kind of deep with some old, unsupported equipment.