Risograph GR 2710 paper jam error but no paper. Can't clear

[Dnayld]

I recently acquired a riso gr2710 duplicator and I have been having a lot of trouble with the feeding. It jams up on the second print every time at the 5 indicator on the control panel. I am a letterpress printer by trade so I am used to trouble shooting much simpler machines and I must admit I feel lost and the user manual is only helpful to a point. The real problem I have now run into however is that the machine is detecting a paper jam at the initial 5 position when there is no paper present to unjam, giving me no way to clear the alert and move on. I don't know where the sensor is that is being triggered or how to appease it. If anyone could give me any pointers on how to get past this I would be eternally greatful. I feel stumped. I also noticed two green adjusting knobs at the front of the paper feeding tray that are not mentioned in the manual at all. I wonder if those could be used to help me with the general feeding issue. I included a photo of them with this post. Thank you for any help that can be given.

[Iowatech]

If you are still here, I have some suggestions that may or may not be useful.
First of all, I don't think the green dials in the picture play a part in the problems you have described (but I may have misinterpreted your post, sorry). The left dial adjusts the pressure between the feed roller and the stripper pad, and the right dial adjusts the angle of the stripper pad in relation to the feed roller. They were meant to allow patient and thoughtful people the ability to experiment with those settings to feed a wide variety of paper stock.
I've been offline for so long I don't remember exactly where position 5 is, but I'll give this a shot anyway and if I'm wrong you can call me rude names or something (sometimes that's how I learn). I'd guess that the receiving sensor is blocked by paper dust. If you look at where the paper comes out of the machine, you will see a teardrop shaped hole in the metal guide, if I remember correctly it is in between the middle belt and the rear belt. The guilty sensor is located in that hole. Clean that and you might be done. Don't use compressed air (unless you are outdoors), when properly used all duplicators build up massive amounts of paper dust, and a badly aimed blast of compressed air can cause an unfortunate mess.
Hope that helps.