Thanks of your input. Taking a root-cause-analysis approach I started with the light build box and found that inside of it the power plug receptacle had blown black gunk out of the vent hole in the bottom this was why it would start up without the light bulb device but with the lightbulb in series it was limiting the power available to start up properly. Using your suggestion I found that the main power relay continued 'chattering' after the amp off power switch was replaced so that is the next replacement but probably also indicating that there is some ghost voltage flowing to the relay, perhaps the diode across the relay may also be faulty, will replace for good measure.

Yes I have a schematic, attached

The biggest lightbulb I can find is 140W. I am trying to test a Solid State Amp (Jamo) when I connect to Amp via the light build it glows slightly then when I press the ON button the the amp it glows REALY bright (doesn't blow) and the amp turn off.
Is this indicating that I need a bigger light build or indicating a direct short in the power supply.
Interestingly if a plug the amp straight into the mains the amp now works some of the time.
There are 4 10000uf caps in the power supply, perhaps this phenomina is just the caps trying to charge ? and thus a bigger build is needed perhaps.
With the amp running it is drawing 0.14 amps without speakers attached so not a big load.
Any assistance for this newbe would appreciated.