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Hi.

I have an old Korry 433 i think it is. I cant get the INPO label to light up. All the other interfacing of the switch is complete. But no luck with the INOP lights.

I have tried to use a multimeter against the lamp connection without any luck.

help needed =)

I looked up the lamp serial number and it is 5V. I removed the caps and tried to light up the lamp directly but it didnt work...

Hm...

If it's an incandescent bulb it might have blown. If your multimeter shows open-circuit then it has.

If it's an LED it probably hasn't blown, but you have to have the power leads around the right way.

Kurt,   The upper lights are 5v and the INOP lights are 28v.
There is a diode and transorb on a little slide-in PCB inside the switch.

If you remove the 2 screws from the back of the switch and slide the retaining cage off, you should see a label on one of the sides showing which terminals do what.

If not, they should be the same as the NG terminals:
13 & 15 5v Backlight (switch must be in for backlight to turn on)

warning lamps 18: +28V    17: Ground

Thanks Mick and Ame.

As always you are Correct Mick. I tried it and it worked like a charm!

Unfortunatly the other bulb is blown so i have to replace it in some way. I can get the caps out but it seems that it is one unit and i am afraid to brake it if i try to open it.

Have any of you changed one of these bulbs before?

I found a spare korry 318 and used its bulbs, it is the same partno.

And voila it worked.

Turned out you changed bulb the same way on the 433 as on the 318.

Thanks alot for your help, this forum is truly great!

And many thanks again Mick.