Not enough info, can you attach photo's of the back box boards?
GI's are fused off the interconnector board.

check for voltages at the fuses.
I Don't have a taxi but is there also a fuse under the playing field?

I would also suggest checking DC voltage at the coils, and there are also GI relays that you should check too.
I don't know if they control all the Gi's or not.
No Gi's in the back box either?

Also check the wire connectors at the transformer, all the yellow wires at the transformer are your GI power supply, that connector might be burnt.
might explain why no gi's at all.