I have a couple of tests you can run to narrow down the Play field light problem.

(Jumper with the power off)
1. Jumper the lock re. (a wire with alligator clips) Blu-y-w and G-y-w. Turn on the machine and see if the lights appear.
- if the lights work clean and gap the lock re. Make sure the contact moves when the lock re. coil pulls. Sometimes it looks right but a good connection isn't made. (I know, this is my most common issue).

2. Remove the fuse and test for continuity
- if blown replace and test. If blows again then you have other issues.

3. With the Jones plug, unplugged.
- Check for continuity of the blue wire between the Fuse and Jones plug.
- Check for continuity of the Yellow wire between the Transform and the Jones plug.
- Check for continuity of the blue wire between the Jones plug and the light.
- Check for continuity of the Yellow wire between the Jones plug and the light.

If one of these fails then you know which wire to trace.

4. Jumper the blue wire at the Jones plug (Connect the wire on male and female side of the plug).
if the lights work Clean the male side of the jones plug

5. Jumper the Yellow wire at the Jones plug
if the lights work Clean the male side of the jones plug