Sizzling 7's is a 3CBP (3 coin buy a pay) Type zero game....it's not a multiplier game.
Contact NLG member named RB....he may have chips you want.
There's absolutely no need to use a clear chip.
You're not changing the coin denomination nor stuck in a the "[61-1] Loop".
There's "another possible issue"...>>>
The "reels locking in place" is a good sign.
That means 24VAC is getting to the MPU.
But there's no indication that the display is getting any power?
Fluorescent lighting uses different power from the power supply....the 115VAC household current.
Check the small black Molex that connects to the back of your display.
Stick a multimeter onto the pins and tell what voltages you're getting?
I wish you would have told us if you have the long reel glass display or the smaller rectangular one that's located up above the bill acceptor (if there is one).
Check the pins underneath the MPU to see if any are touching each other or bent out of place.
Make sure the GAME and REEL eproms in their respective sockets in the correct orientation.
There woulld be either a notch on one end of the chip body or an indentation circle on top one one end.
These would match the notch etched directly upon the circuit board surface next to one end of the socket.
It's possible too, that there's a folded chip leg UNDER a chip body that you cannot see.
This is what a small bent screwdriver is good for....or a chip puller.
http://www.newlifegames.net/igtbible/IGT%203CBP/Game%20Library%20-%20S-Plus%20-%20Sizzling%207%20(3%20Coin%20Buy-A-Pay).htm