backlight on gauges not working... ideas?

[GiJOr33]

I've got two Greddy gauges, Fuel Pressure and Water Temp (both with the electronic module that does memory and warning), 3 omori gauges in the center console under the stereo, and a Greddy Boost Guage above the steering wheel... the other day all the lights worked fine, and when i turned the park lights on the gauges would light up. But now none of them do. The dash lights still work though. It only happened after i had the clutch changed, and i rang the guys to see if they had changed anything and they said, nothing but the clutch. So i spent half the day today checking the wiring with the multimeter... power is getting all the way to the back of the gauges and the globes are fine. Could there be something wrong with the grounding? The gauges actually work so i assume the grounds are fine, but i'm not sure if there is a different ground for the lights. It's driving me up the wall... if it was one gauge light that went then i'd think it's either globe or the connection to it. But the globe is fine and it's getting power, and the thing is, all the external gauge lights have stopped working. I've checked the fuses too... (unless there is a fuse in the power line somewhere, but i've checked that they are getting power all the way to the back of the gauge)

It's got me stumped! Any suggestions are very welcome

Thanks

Andrew