Williams Grand Prix (EM) - Reset sequence not completing (..

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Archived from groups: rec.games.pinball (More info?)

Hello,

I'm in the middle of restoring a Williams Grand Prix and my biggest
problem right now is that the reset sequence is not completing and the
score motor goes on forever. Hope any of you EM wizards out there can
diagnose these events and maybe tell me where to look.

1. I power on the game
a. Lock Relay fires and stays locked.
b. "Game Over" lights in the backbox

.... Here I'm having some problems with the credit counter (a coin drop
increases the credits, but also chimes a bell and increases the 1000
score wheel), plus, no matter how many credits I have I still can not
start a new game with the start button. More on this in another post...

2. I manually trigger the Coin Relay (which should trigger the reset
sequence)
a. The score motor starts running
b. The "No. 2/3/? Reset" relays in the backbox fires in a pattern with
the two leftmost firering at the same time, alternating with the
rightmost. This resets all the score wheels to 0000000 where they stop.
c. After a second or so, the Game Over Relay Latch is fired, and "Game
Over" is no longer displayed in the back box. Instead the ball number
and player up is lit. Player up is 1.
d. The Target Relay is fired and locks
e. Both Bonus Steppers under the playfield locks the reset coil, and
sporadically fire the step down coil (step to 0 because of the reset
coil locked).
f. The two kickers to the left and right of the playfield fire and kick
e. The target relay is de-energized and the whole sequence from d is
repeated.

I've opened and cleaned the two bonus steppers, and I'm fairly sure that
the two player steppers (backbox and bottom cab) are zeroed. Same with
ball count which displays 1. And all the score reels are zeroed. So it
seems that everything is zeroed, but this is not passed on to the part
supposed to stop all this noise :) Is this possible? Also, what has the
Target Relay got to do with anything? Seems like it's firering in every
little sequence I've tried.

Thanks for any help I can get!

Tor Arne
 
Archived from groups: rec.games.pinball (More info?)

after you reset the machine and all score relays are zero pull your
reset relay back to de- energized position. if it stays in that
position when you let go then the machine should play. if it does not
stay in that position then check your coin mech and front door. .your
welcome to emal me at brshsg@yahoo.com if you need any help. norm in
missouri
 
Archived from groups: rec.games.pinball (More info?)

Grand Prix - great EM game when the ball rips through the spinner and
the playfield lights run up. The reset problem could be two problems.
I believe on the score reel switch stack there's '0 index' AND a run
score motor switch. They should stay in sync (open/close). Also, look
at the A,B,C,D drop targets and make sure their switch is closed when
target is in the up position. Really need the schematics to see the
other switches that factor into the score motor running. Keep at it -
you'll get it soon.

billg
 
Archived from groups: rec.games.pinball (More info?)

Tor Arne Vestbø wrote:

> I'm in the middle of restoring a Williams Grand Prix ....

Pictures to the question at http://williamsgrandprix.blogspot.com/

Tor Arne
 
Archived from groups: rec.games.pinball (More info?)

you need to pull the main board out and inspect all contacts. Keep the
coin door plug unplugged also when testing(you have to put a jumper in
to complete a/c circuit.)
I also think you can disconnect the playfield from main to help trouble
shoot. I think also you can have the main board all by itsself powered
up and reset it that way also to help isolate the problem.

DONT GIVE UP! You will figure it out. I would start with only the main
board by itsself (with jumper for a/c) and trip the "player reset"
relay to test. I t should reset and motor should stop.

Grojohn
 
Archived from groups: rec.games.pinball (More info?)

A/c jumper should be top two plugs (blue and red I think) on coin
connector
 
Archived from groups: rec.games.pinball (More info?)

Tor Arne Vestbø wrote:
> All right,

I did it! :) Thanks to you guys! And some nice schematics I got hold of
last night 😉

"The Outhole Problem" was due to the simple fact that I didn't manually
trip the outhole switch :)

I also decided to go through the whole backbox and clean and
adjust/check every single one of those damn score reels. After 10/20 I
plugged it in and it worked! :) Score motor stops and Outhole relay is
triggered and the whole reset sequence completes! Hurray!

Now is testing all the targets and game rules.

I will be back :)

Tor Arne
 

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