Vintage Synth Repair

Hi folks,

I wonder if anyone has any ideas about this one.

I bought a new backlight for this Korg Wavestation EX... it didn't work. I checked the pins on the power supply feeding it...  and it lit up one of those neon A/C test screwdrivers.

So I assumed the light was faulty and got a replacememt. Today I wired up the new backlight - on a loose wire, just to make sure it works and... nothing!

I am getting power on the connector... and I have two backlights that don't light on it.

Any ideas/suggestions please...?
Cheers,
TOM