Tray 5 won't rise on bizhub c8000!

[AB1984]

I've got on important job on running crappy perfed paper that kept jamming Anyway (see previous post), and now to make matters worse tray 5 won't rise, so I've got the job running out of tray 4, which means more bending and weakening of the perfs (hence More jams :-s!)
I don't have time to take the thing apart like I would normally do to try and figure out the problem, does anyone know the most common reasons why a tray won't rise?

I've taken the tray out, cleaned rollers/sensors etc. to no avail.

any help appreciated!

[remati]

I've got on important job on running crappy perfed paper that kept jamming Anyway (see previous post), and now to make matters worse tray 5 won't rise, so I've got the job running out of tray 4, which means more bending and weakening of the perfs (hence More jams :-s!)
I don't have time to take the thing apart like I would normally do to try and figure out the problem, does anyone know the most common reasons why a tray won't rise?

I've taken the tray out, cleaned rollers/sensors etc. to no avail.

any help appreciated!

..normaly is one belt out of the stay.....

[DigiMan]

I've got on important job on running crappy perfed paper that kept jamming Anyway (see previous post), and now to make matters worse tray 5 won't rise, so I've got the job running out of tray 4, which means more bending and weakening of the perfs (hence More jams :-s!)
I don't have time to take the thing apart like I would normally do to try and figure out the problem, does anyone know the most common reasons why a tray won't rise?

I've taken the tray out, cleaned rollers/sensors etc. to no avail.

any help appreciated!

I agree with remati,had this thing couple of times(on 1051s PFU's),take out the tray and look inside the PFU.On the top one of the belts is out of place and its blocking the sensor that detects paper.