starting on a grand prix that's been sitting a long time. not sure how or where to start on this as there's a lot going on. i'll lay things out here and maybe someone can guide me on the first thing to start looking at.

give credits and ensure the 2 contacts on credit wheel are closed, power game on, head lights up but no playfield lights, push credit button and it cycles up to 2, 3, or 4 players. most reeels are zero but ones that are not zero do not attempt to spin to zero. no flipper action or playfield target action except roll over switches, those acknowledge and make a click.

FYI, this a late model game that has the SS sound (no it doesn't work)

made some progress here. cleaning the switches on scoring reels and we're all zeroing out so far. dirty jones plus connection and the playfield has lights and most targets working. here's where we are now.

1-turn machine on and hit credit button,
2-reset process initiates and reels zero, scm keeps spinning and no 1, no 2, and no 3 reset relays keep flickering, while also resetting L & R bonus units.
3-scm never stops and no 1,2,and 3 reset relays never stop flickering unless i manually dis-engage the reset relay.

i believe we're getting through paragraph 5, but will have to double check to be sure. i see the bonus units both continuing to keep resetting, the player, coin, and ball count unit reset, and ill have to check the game over relay reset coil. the no. 1 2 and 3 reset relays just keep cycling and only stop if i release the reset relay manually. somehow the reset relay is being held on. thinking maybe the game over relay reset coil could not be firing? i'll double check al this but again, it's getting to the point of reset relay being held on, scoring reels at zero, and the no. 1, 2, and 3 reset relays just keep firing.

to triple check my understanding; all 3 of those switches per score reel are in open position for zero, correct?

that was it! one switch was just barely making contact still, opened that up and cleaned it a bit; now it's resetting and releasing the reset relay accordingly. will keep digging in and post back with the next issue i need a hand with!

looks like we just have some playfield/target issues now. here's where we stand.

-neither pop bumpers or targets work, but one does have a light lit up.
-A, B, C, or D bulls-eye targets will fall down and pop back up after 2 fall, but no scoring action.
-the 2 lower side targets right before ball drain that shoot the ball when their hit don't work or score.

is there a relay that supply's power to these areas that i should start looking at?

**noticing during a game reset cycle, the 10A fuse under the playfield blows. is this fuse contributed to the problem areas im having?

FIXED THIS, had a bad shorted kick out coil on the lower targets and disconnected that, replaced the 10A fuse, and now the pop bumpers and lower target kickout(one side) are working. still no scoring on the bonus units or bulls-eye targets though

games just about dialed in, minus a few things. when the left or right stand up switch is hit to advance the left or right bonus, it scores 500 pts through the 500 relay. most time this works fine, but every now and then it will stick the 500 relay and just keep spinning the scm and racking up points. i checked the switches on the 500 relay and cleaned them, all appeared to be ok though and it made no difference. anywhere else to look for the sticking 500 relay?

that was another possibility i thought and checked it, seemed it had plenty of gap when the finger was in the divit of the cam and closed when riding on the cam. will double check again tomorrow though