[CiderCid]

Thanks to broadgage, The Philpott and teetoon for your replies.

First let me try to answer some of the points raised.
The information I entered from the box as they have been with me from new and therefore know the information relates to the set. None of the current bulb have a white tip, so assume I have no fuse bulb.
I have tested with a volt metre the 18 remaining/whole bulbs and these have continuity. Apparently, the box says even with a bulb blown, the set should still work, so I assume as the bulbs have come away from their screws, (the reason I have removed them) explains why none a lighting up.

teetoon, thank you, these are exactly like mine, except he describes them as Olive Lights and for outdoor use, where-as mine are called Cone Lights and for indoor use. The ebay seller made a good suggestion about buying a dimmer to run them through.

broadgage, thanks, I never understood I can swap out the bulbs for a different wattage, so that will be my last scenario failing everything else.

Thanks
Kenn