LaserJet M477fnw - persistent yellow toner streaks from third tray feed

[ClairelyClaire]

I have a LaserJet M477fnw I've owned since it was new. I added a third tray some time after I bought the printer, which I use for junior size heavy weight paper for the most part (32lb). An aftermarket yellow toner cartridge failed awhile back and appears to have leaked some yellow toner somewhere in the internals. The result is streaks of yellow toner along the transfer film, which can I manually remove with appropriate tools.

I can print from Tray 1 without any problems. I can print from Tray 2 without any problems. When I run a print job through Tray 3, however, the streaking starts and can be pretty bad (a solid layer of toner on part of the transfer film). I've replaced the toner cartridge and inspected the rear of the machine today. I found some yellow toner under the padded, spring-mounted feed roller at the rear of the machine, but cleaning that didn't resolve my problem.

[Valsimot]

If you on print pain paper from tray 3 how does it print. 

[ClairelyClaire]

Sorry for the delay in following up on this. I did some color test prints with copy weight letter size paper from tray 3, and I'm still getting yellow streaks, along with yellow toner deposits on (what I think is) the imaging belt:

[Valsimot]

If the print from tray1 is OK than it's not transfer belt. Can you please confirm that printing from Tray1 is OK.