I had no pre check done either by the way aren't the board components on my WH20 soldered direct to the board ? What's the difference?

Peter

WH20 is through hole mounted... larger components whose legs go through the PCB and then soldered. With some skill, anyone can fix these so long as components are still manufactured.. solder sucker, soldering iron, component and away you go.

ACDC is Surface mount component... very small components that are float soldered on. It is very difficult for anyone to repair this.. the legs on the components are so small its a real issue to see what you are doing. Most people wont have float solder capabilities and testing these tiny components is also extremely difficult. A surface mount board is pretty much a throw away item that gets replaced. No problem so long as the boards are still being made.
Mike Homepin DELIBERATELY makes all his boards as through hole so they can be repaired... it would be cheaper for him to supply surface mount... but this is pinball and 90% of us can fix our own games. Mike understands and recognises this and so supplies a product to his market.
Stern who are now targetting the home pinball enthusiast market have not taken this into account.
We all know from experience that transistors fail/ burn out due to a stuck switch etc. What happens when the warranty runs out ( how long is this?? 3 months... 6 months.. a year?) and a transistor blows taking out its driver chip also?.. Most people will have to buy a whole new board... like i say, no real issue so long as the boards are available, but if i was an ACDC owner it would be something that i would want to address so i can keep my game running 10 years plus