In my experience, the I/O and the sound boards have always been working - it's the main board that is a bit of a gamble.
You can get the game to boot with just a main board and an IO board - if you don't connect the I/O board it will just display a blue screen.
The main board and I/O just need...
You need to have a properly connected working IO board or you get the blue screen - maybe double check all of the connections from the main board and power to the IO board?
Here's mine inside a Mini Cute with the Nanao monitor that can handle medium resolution - we also added a 4PDT switch on the frame to select between 15 and 24khz - I believe it's not safe to switch whilst it's powered on - so beware if you try the same mod.
We still need to tidy up some of the...
You'll need to hook up 5V & GND to the main board (lots of connections to spread the load of all that current)
Note - for the 5V & GND to the main board - you'll want to take directly from the PSU and not from the JAMMA edge - it's too much current for that contact size apparently, it'll work...
I ordered them through Zenmarket - you have to be very careful when ordering because they might show a picture of something and then in the text say 'not this one' or 'different wheel type'. Plus prices can vary massively.
Using the model numbers from the website I attached is the most reliable...
Hammer casters are what I believe are used for most candy cabs.
E2 & 3 use
2 x 320E-N (Nylon) 50mm (swivel)
2 x 320SR-N (Nylon) 50mm (fixed)
You should double check the bolt pattern on their website before ordering