Wurlitzer Jukebox One More Time 1015 Problem

I own a Wurlitzer Jukebox One More Time 1015 (CD)
I have a problem that I am not able to fix,
Problem is that after a selection the carrier turns constantly,
I viewed the trouble shooting manual, and I found that the reason could be:
- Plug "black" in the SCC unit is in the reverse position
- Faulty lamp in the carrier light gate,

This is all the info I could find in the manual that I got with my Jukebox, and the only info I could find online.
I need assistance since I am not able to fix the problem, I am not sure what is Plug "black", and I am not sure what is the lamp in the carrier gate, how do I know if it is faulty, and if it is faulty how do I replace it,

Any ideas anyone?

Thanks!!!

Hi!

Some info about it...

- The "black plug" refers to the plug that is connected to the black-coloured connector at the Selection&Credit Computer (SCC). If the problem appeared after unplugging cables from the SCC, just look if that plug was connected at wrong polarity afterwards.

- About the light gate: When the front door is open, you should be able to see a dim light at the front side of the CD carrier (the small black box where the latch lever resides). If there's absolutely no light to be seen, check the small bulb inside that box.

I hope it helps.

C U
Catboy (Kai)