Problematic electrickery... Help please!

[Jedward]

Ok I have a problem that has got me stumped

I have a C4.2 running the following setup;
SP Reventon S ESC
SP 13.5 v3,
SP sensor cable
nano tech saddles
Sanwa gemini trx and 451RX
The set-up is not new and has run before without issue.

I turn on the trx and rx, the car powers up I have steering but no throttle, nothing from the motor at all.

I have changed the saddles, Esc to another SP unit, the motor to another v3, tried a different sensor cable, tried different battery connectors, checked the servo leads are in the correct ports and pushed in and I still get the same problem?????????

So what is the problem, has to be something obvious right?