s2000 board swapping question

[pinball2000]

forgive me if answered before. I have 4 s2000's im working on . If I swap boards between machines I get rom errors and have to go through the process (key ,test button etc.) to get the game to boot. Was curious if this is normal when swapping boards. Do the machines "know" when a different board is installed thus the rom errors? Do all settings go to defaults that have been programmed in previosly? Thanks in advance! JR

[Tilt]

Yes, it's normal.  There's a 16 kilobit electrically erasable programmable read only memory (EEPROM) located on the backplane that stores the processor identification number (serial number) and other game data.  Each processor board has its own unique electronic serial number, and it is checked against what is stored in the EEPROM during the bootup process.  If they match the machine boots up normally, if not, you get a Call Attendent message in the display, (if door is closed), followed by an EEPROM error (and annoying audible alarm) when the door is opened.  When you turn the key a couple of times the data in the EEPROM is updated, and the machine continues to boot. 

You can have an EEPROM for each MPU board, and if you change them both together the machine will boot normally everytime.  The problem is the EEPROM is difficult to get to on the S2000 as the processor shelf makes it hard to reach.  It's pretty easy to access the EEPROM on Game Kings/I-games and by swapping the MPU and EEPROM together allows you to keep all your game statistics, credits, etc.