Gottlieb Star Rollovers not working

[Slash]

Almost got most of the bugs sorted out of Buck Rogers apart from a couple of flaky globe connections and the star rollovers.

The 2 star rollovers have never worked.  The switches are adjusted properly and when I manually close them they still don't work either.

I have cleaned the switch tips, reflowed the solder on all connections plus checked continuity along different points including the ground braid between the 2 switches and it all seems to be intuitively correct.  I have replaced the diode down on the backelite that matched to the same wire colours going to the rollovers and still no joy.  The Gottlieb's used 1n270 diodes and I used a 1N4148 diode which from my reading is fine to use.

I'm now totally out of ideas what it could be?

[Retropin]

Make sure you have power to the switch... the braid is the power line so a DMM from this to ground should show voltage present

[Slash]

It doesn't look like I have any power to that braid, I can't get any voltage there.

So what's the likely cause of that?

[Boots]

It doesn't look like I have any power to that braid, I can't get any voltage there.

So what's the likely cause of that?

Check the continuity back to the MPU connector

[Slash]

How exactly would I do that?

Put one end of the DMM on A1J711 and the other on the braid between the two rollovers?

Is it best to unplug the connector and stick one DMM lead into the A1J711 slot where it's crimped.

Excuse my ignorance but I have NFI with this stuff despite reading and googling as much as I can.