New Laserjet 4V - toner door won't latch

[Biz]

I just got a Laserjet 4V second hand but never been used, still had packing stuff taped on. When I put the toner cartridge in, I cannot latch the toner door. I cannot see any obvious problem. Removed the toner seal pull-thing. Same problem if the green tabs are removed. The door latches fine if cartridge is removed. Catridge is C3900A which is correct according to specs.

If I hold door shut and do a test page, the paper jams. I didn't get any instructions with it so maybe there is something I was supposed to do before installing cartridge? Or is there a trick to inserting it?

Any suggestions appreciated. Thanks-

Biz

[Biz]

I found out what the problem was, the cartridge had a piecee broken off which opens a flap in the toner catritdge when the printer side door is shut. If the flap doesn't open, the door doesn't shut. So I just opened the flap before shutting door. Now I just have to remember that next time I open the door...
Biz