Quoted from Manny65:

there are 2 powerball proximity sensors, one in the subway and one in the trough - the ball trough sensor (switch 26 off the top of my head) is known to be troublesome. There are aftermarket better versions which aren't expensive so even if it was an issue it's not the end of the world.

Quoted from Manny65:

https://www.tanglestech.com/Twilight-Zone--Trough-Proximity-Eddy-Sensor--Replaces-A-16534-and-A-16528-Switch-26_p_36.html

Quoted from Manny65:

PinballLife have the main sensor board https://www.pinballlife.com/mm5/merchant.mvc?Screen=PROD&Product_Code=PBL-600-0421-00 but often it is the inductor and the connection to the inductor board that is part of the problem, which is why alot of replacements provide both boards to ensure they work well together. I can't find any other US based suppliers with those boards in stock.
With the Aussie dollar atm the Tangles board set is US$75 compared to the $50 for single board from PinballLife or $95 for the board set from Big Daddy (although they are out of stock)
Anyway if you were interested, reach out to malcolm (aka Tangles) for shipping costs etc

Quoted from Green-Machine:

I’m putting in my TZ a color DMD this weekend. Any advice or is it pretty simple?