Can't Run Anything but 11x17

[WoodsleePrint]

I just got a "new to me" GR3750. Feeds ok but everytime I try letter, it jams up after it has passed through the ink cylinder/pressure roller. Sheet is not stuck on the ink cylinder. The exit belts are polished in appearance. Is there a vacumn that is supposed to pull sheet down? If so, how do I check it. Thanks

[20gaugeO/U]

There are 2 sensors on the feed table. Is the one on the part of the table that folds up covered in dust and it thinks the paper is longer than it is?
Test mode 64 is the separation fan. TM 69 is the suction fan in the paper exit unit. TM 62 is main motor drum rotation. Do the 3 rubber exit belts still rotate if you touch them with your hand? If not you have a loose screw. Is there a puff of air coming out on the orange paper separation finger? If not you have a problem with the pump area behind the motor control PCB.

[WoodsleePrint]

Sensors are clean and register paper correctly. Test mode 64 works and fan blows well. TM 69 works the suction fan well. TM 62 works the drum rotation properly. The 3 rubber belts rotate by hand.

How do I check the orange finger for puff of air? I don't think its the problem though.

The paper makes it through the ink/pressure rollers and then seemingly gets stuck (as if to much vacumn maybe) on the rubber belts (they are polished in appearance). Hope this helps.

Also is there a TM tha makes the black plastic guides (on either side of the rubber belts) go in a forced down position that will still allow me to feed paper thru?

Thanks!

[Joel]

i once encountered the same problem, but i try it by reversing the original that i I'm printing placing the solid part of the original at the bottom part then re-scan it and it solved the problem. the other thing is placing a separation claw (cardboard) on top to help the paper release from the drum.
hope this help in your problem

[WoodsleePrint]

Hi Joel,

It's not an image related problem. Very little coverage on sheet. The sheet comes off the drum, no problem, but acts as if stuck on the exit belts. Then next sheets aren't ejected properly and eventual jam. Thanks for your ideas though.

[20gaugeO/U]

Pull the drum out and note the how the rear of the drum is keyed with the drive on the rear wall (narrow pin at 12 and wider bit at 6). Set drum asside. Run test mode 62 and feel or listen for the puff of air from the orange sep finger. It happens once every rotation or every 3 seconds or so. TM 60 is slow rotation so you can get the key to line back up.

Does the jamming occur on all 5 speeds? If it doesn't occur on slower speeds then there is a cluster of drive gears, 1 way gear and clutch that works with the exit belts. The clutch and 1 way gear only kick in on the higher speeds. You can tear it all down and clean everything.

The other thing is to the left and right of the 3 exit belts (when looking over the exit tray) are some triangular shaped guides probably made from black plastic that cup the paper upwards for delivery of the paper to the exit tray. Eventually the paper cuts gouges in these and will actually stop certain sizes. You can file them down and put a layer of thick packaging tape over them if needed.

[WoodsleePrint]

No problem with the "puff of air". I filed the side triangular guide down (there was a definate groove worn in for letter size).

You mentioned speed setting. Seems to exit paper fine at speed settings 1 and 2. Problem occurs on 3 and above. With the back cover off, I can see into the gears you mention, and they appear clean and free of paper dust. Exit belts will turn in one direction (towards exit) but not the other way, and I don't want to force them. I don't know if this is a clutch test..... Thx

[20gaugeO/U]

Swap the entire assy from another machine or tear apart that assy and clean the clutch, the white 1-way gear and take the shine/smoothe surface off the shaft it rides on. Even after a good cleaning I have had them still not work right. The only carstock part I carried was the 1-way gear. P/N: 019-13602 A word of caution, there is a small brass bushing in the assy. Don't let it roll away when you split the assy in two.

Good Luck