I am the original owner of my Ghostbusters Premium purchased in October 2016. I turned the game on last night, and the game would not complete the boot process, displaying "Locating Node Boards, 9 Node Not Found". I restarted the machine three times, receiving the same message.
After searching Pinside for similar reports, I proceeded to unplug and reseat all Ethernet cable connections in the backbox, in the cabinet, and under the playfield. The same message displayed when attempting to boot when the machine was turned back on. This time, after displaying that node 9 is not found for about 20 seconds, the game completed its boot process, but the majority of the lights in the back section of the playfield were dark, and I noticed smoke emitting from under the playfield accompanied by a burning smell. Looking under the playfield, I saw the smoke coming from the left magna-sling magnet. The metal bracket holding the magnet in place was extremely hot to the touch, and the black tape-like covering surrounding the magnet looked like it had melted some. I disconnected the molex connecter of the magnet assembly to remove its power source to prevent any further damage since it appears that the magnet may be locked on.
I have also removed the Node 9 board (520-7017-72A) to check for any damage, and nothing looks burnt/blown and I did not see any solder issues. All transistor legs look to be intact with the board.
I have installed the recommended Service Bulletin kits years ago as they were released (#189 "Core Node Stabilization Kit 502-7061-00", #190 "Capacitor Service Kit 502-7060-00").
Is there anything else I should check? Is my only hope to replace node board 9 and the magna-sling magnet assembly?