Wiring a T5 Ballast

I recently purchased a 5 foot tank that has a T% light fitting included.

The seller said "sometime you need to wiggle the two foot tubes". Gave it to my (2nd year apprentice sparky) son to check out and he said it needed a new ballast.

I got a new ballast but be damned if I can get it to work. Looking for ideas/suggestions (other than asking no good lazy rotten good for nothing so to look at it).

I am replacing a 2x24 T5HO ballast with a 2x24T5HO ballast of slightly different configuration.

The orginal had 1 pair red wire (power in) on one side and two pairs of white and black wires on the other - one white pair and one black pair per tube.

The replacement has 1 red pair (power in), one black pair and one blue pair on one end and one black pair and one blue pair on the other end. The case is labled "Lamp 1 Blue", "Lamp 2 Black".

Seems straight forward but no combination of wires (including mixing the blue and black on one tube) seems to "make light work". I have even bypassed the fittings attaching the ballast wires directly to tubes, and removed working tubes from another light fitting. I have 230V AC on the multimeter feeding into the ballast but no reading on the outgoing wires, which apparently is normal according to net research.

Other than the new ballast being a dud, What am I missing?

Cheers,
Scott