Fuse? When you write connector posts do you mean the jones plugs?

Have a look at the schematic on ipdb.org: http://www.ipdb.org/machine.cgi?id=1733

There are two 15 amp fuses for the lights, remove and check for continuity if they are not obviously blown.
From your description it sounds like the brown/yellow <- fuse -> brown one is suspect.

back box lights should be fused. ran in series, maybe broken ground wire. check for voltage at jones plug (use color wire to identify)Credit light and knocker should work off a switch at the credit stepper

Yep, the location they "break off" at is at the backbox fuse in the lower left corner of the bottom cabinet, they are not fused together with the rest of the lights. I'm assuming you have playfield general illumination lights working?

Make sure the fuse holder isn't corroded either. Also, did you check the fuse with a multimeter rather than just looking at it?

could also be the fuse holder.

The knocker is grounded by the end of stroke switch that is on the credit wheel add coil.

Test for voltage as I have seen knockers that have locked on and the coil has failed. start by checking at the eos switch.

Glad you got the problem solved. For the knocker...is it firing and no sound or no fire at all? 1st easy step...make sure there IS a 'plunger' inside coil and or the 'tip' is not missing that strikes the plate. I've found that before.

Check the contact on the third coin, that is the nc, check contacts on 25 c. and 10 c, nc.
Those three have to work well to get the knocker working.

25 c. there are two contacts on it, one no closes when a coin is inserted, one nc, is closed in rest position. This one makes the contact for the knocker via a nc contact on the 25 c.

Referring to the schematic you could use a jumper to fire the knocker to see where along the circuit it fails.
For instance, you could jump the R-Y-5 side of the knocker coil lug to YELLOW return on the transformer.
Then if you manually close the replay stepup EOS switch the knocker should fire.

If that works, move the jumper down the circuit one switch at a time as shown by the schematic: 10c relay make/break, then the 25c relay make/break and so on.

knocker_jumper (resized).jpg

get a new blade for the one thats broken from pbr.
you can replace the whole blade, or just cut the contact end off where it exits the bakelite, and remove the switch stack, seperate it, and slip the new blade in on top of the old one.
the two will contact each other, and you will have a new lug to solder to.
you are gonna want to service those coin switches, they need to function correctly, or no knocker, and possible other issues.