[Jamming] GR3770. Paper Jam, check feed area???

[Kev]

Machine has about 2.2 million copies up. Feeds usually 2 or 3, can do 6 before this message comes up. is never a paper jam. last sheet drifts out maybe half way on to the output tray, & usually showing an extra 40mm or so margin on the lead edge. SO. Have really gone through what I regard as the usual culprits. Has new scraper & pick-up rollers, new scraper pad. Table lift is spot on. Timing , & pressure hook adjustment. But only actual thing I can find wrong is that the last sensor in the train, Paper receiving sensor #2 is not working. i.e. does not respond to a sheet of paper. The manual only tells me that if that sensor thinks a sheet of paper is over it, it will stop the machine. Nothing in there that I can find about if it doesn't ever record paper going thru. Wondering if anyone out there has had experience with this particular sensor not responding. The non-response is shown in Test mode, and also by non-response from the LED RCV2 on the PCB. Have attacked the relevant connectors with contact cleaner to no avail, so would be very appreciative of first hand experiences before I go searching for a replacement for the sensor. TIA.

[Exok]

Re: GR3770. Paper Jam, check feed area???

I would find another like sensor in the machine and swap it to see if the problem follows the sensor or the sensor location.

[Kev]

Re: GR3770. Paper Jam, check feed area???

Thanks for the reply. Have an identical machine, but with a 7000 sheet job coming up before Easter, don't want to tempt fate by swapping parts out of the good machine before then. Seems strange that it should be pin pointing the feed area if this sensor is the problem.

[Iowatech]

Re: GR3770. Paper Jam, check feed area???

Have you tried resetting the machine?
You might also want to take the double feed prevention switch in the scraper unit out of the picture.

[Kev]

Re: GR3770. Paper Jam, check feed area???

Interesting you should mention that switch. Had already wound it down well out of the way, but while I was in there thought the connector was not as firm as I would have expected. Actually thought of putting a small cable tie around it to stop it coming apart.When I get back to it, I'll try shorting out the whole circuit back at the PCB. Will also try a reset. Input much appreciated. Thankyou. ( will get back with results, but probably be a week away. We print the local paper on these believe or not, & due out Wed._ Sunday here now.)

[RRodgers]

Re: GR3770. Paper Jam, check feed area???

Will the machine run at all on speeds one and two?

[Kev]

Re: GR3770. Paper Jam, check feed area???

Nope, same on all.

[RRodgers]

Re: GR3770. Paper Jam, check feed area???

Check guide roller