Hello,

i try to repair a William Space Shuttle (System 9)

history :
bad display :i change caps and resistor on power supply : +100 and -100v Ok, the display works
No EPROM : I burn the 2 epprom : Test sound and voice ok, lamp test and solenoid test ok (except right flip)
All solenoid fire on power up : I replace the NE555 : Fix it
One solenoid was burning : change the 2 related transistor : Fix it (he fire on startup, but i read it's happen on williams)
also change the batterie : Didn't show the game id anymore on startup; but show the number of credits and 00 on player one instead.

I press Sound test switch on cpu : sound and voice ok
i press Test switch on cpu : all lights flash one after one (look like test all), and still 0 on cpu digit (test ok ?)
i can run test (lights, sound and coils) via the door switch

MY PROBLEM :

I can add credit through the coin switch (it make sound and add credit on the display), but when i press the Add player/start game bouton, all coils fire a second together, and nothing happen. (no game start )

Any idea ?

Thank you for your help (and sorry for my poor english)

Thank you for your help !
i try the switch test :regarding to the switch matrix table, i do have a complete collumn of switch who didn't work (including the three ball ramp )
It's looks like a playfield issue
The switch "work" on the display when i strap pin between 1J8 and 1J10, but weird thing, the pin of 1J10 look like reverse (i strap 1J8-2 and 1J10-1 and switch 16 beep, instead of 9 on the matrix table, if i pick 1J10-1, switch 16 beep, instead of 9....)

I try to find the all col issue on the playfield first, and i'll look at this after.

i'll let you know
thanks again

it's working !!!
i do have a cuted wire in a switch column, i fix it , all the column switchs works again, and the game can start !!!!!
still have few things to fix (contacts, lamp, ..) but electronic is ok and i know i can handle the rest

Thank you for your help !!