Regarding the far left button, that's the coin return button which is normally purely mechanical. I have heard people will sometimes bend a coin switch actuator in a way that pushing the coin return button activates the switch. Doing so would either add credits to the machine or start it depending on how the credit plugs are set up.
Regarding the ball sitting in the return, first thing I'd check is the ball return hole switch. If that isn't the problem then maybe I can help.
I don't have a Funland schematic but the following is from a 1969 Gottlieg MIBS. The ball return arrangement may be exactly the same as your Funland or completely different. Be sure to compare this information with your own schematic especially score motor switch assignments.
I am assuming you can press the start button or the modified coin return button and the machine resets. The sequence banks reset and the score reels all zero out but the ball just sits in the ball return hole.
Questions:
a. Does the score motor keep rotating indefinitely or does it stop?
b. Before you press a button to start a game manually operate the Ball Return relay with your fingertip. Does the relay lock in under your fingertip for a moment -and- the Ball Return solenoid kicks to serve the ball?
This is the ball return sequence for MIBS:
1. The game's reset sequence is started, the XB (Game over relay) goes off.
2. The ball is sitting in the outhole so that switch is closed.
-
3. That allows the O (Ball return) relay go go on through the XB (Game over) relay, outhole switch, the TX (Tilt) relay and Motor 1C.
1.jpg
-
4. Cam 1C eventually opens and the Ball Return relay is held on by its own holding switch through motor cam 2B.
2.jpg
-
5. Since the Ball Return relay has gone on, it energizes the Ball Return solenoid when Motor Cam 4C closes which serves the ball into the shooting lane.
3.jpg
-
6. Cam 2B opens to turn the Ball Return relay back off.
4.jpg
-
These are the MIBS score motor cam locations:
Motor_Locations.jpg