GR3770 - Hook lever not engaging pressure lever

[Fayez Butts]

Hey guys, I feel like this has to be a setting turned on somewhere that I'm missing or something. I haven't done much printing at all with this machine, but a friend was having trouble, tried to fix it, and now this is happening. They didn't touch anything behind the back panel, though. Any ideas? At the end of the video I press SW1 so you can see the resting position of the hook lever, and it looks fine to me. I feel like there is a really simple dumb fix for this as the machine has been working surprisingly well up till now

Video:

[Iowatech]

Re: GR3770 - Hook lever not engaging pressure lever

I have two guesses:
First the easiest and kind of likely guess: if you haven't reset the machine by holding down the "Reset" key for 5-10 seconds while turning the machine on you should do that now and see what happens.
And the hardest but most likely guess: one of the wires from the pressure solenoid is broken inside its insulation. The ends of broken wire are still close enough to each other to occasionally connect, which is likely why the pressure lever moved for a moment at almost exactly the wrong time. If you have a service manual for the machine, there is a test mode for the pressure solenoid which you can engage, then flex the wires coming out of the solenoid to test for that.

[Fayez Butts]

Re: GR3770 - Hook lever not engaging pressure lever

I have two guesses:
First the easiest and kind of likely guess: if you haven't reset the machine by holding down the "Reset" key for 5-10 seconds while turning the machine on you should do that now and see what happens.
And the hardest but most likely guess: one of the wires from the pressure solenoid is broken inside its insulation. The ends of broken wire are still close enough to each other to occasionally connect, which is likely why the pressure lever moved for a moment at almost exactly the wrong time. If you have a service manual for the machine, there is a test mode for the pressure solenoid which you can engage, then flex the wires coming out of the solenoid to test for that.

Thank you!

Your second guess was pretty much something like what I expected may be happening, so that was helpful to go through those steps. Unfortunately it looks like the wiring is fine. The solenoid actuates whenever I press the start button in Test Mode, so now I'm really confused.


As for your first idea, I have pressed the Reset button many times to clear this error message, but maybe there's something I'm missing?



Usually there's just a piece of paper sitting under the drum as you'd expect from it not getting pushed through by the pressure roller.

[Fayez Butts]

Re: GR3770 - Hook lever not engaging pressure lever

I have two guesses:
First the easiest and kind of likely guess: if you haven't reset the machine by holding down the "Reset" key for 5-10 seconds while turning the machine on you should do that now and see what happens.
And the hardest but most likely guess: one of the wires from the pressure solenoid is broken inside its insulation. The ends of broken wire are still close enough to each other to occasionally connect, which is likely why the pressure lever moved for a moment at almost exactly the wrong time. If you have a service manual for the machine, there is a test mode for the pressure solenoid which you can engage, then flex the wires coming out of the solenoid to test for that.

Thank You! Your second idea definitely jived with what I expected and helped me figure some stuff out. Unfortunately it looks like the wiring and solenoid are working fine; the lever actuates whenever I press the start button in Test Mode.

As for your first idea, I have reset the machine many times, all to clear this error message:



As you'd expect though, the paper ends up just sitting under the drum but the error stays after I remove it. Is it possible I've missed something or a jam somewhere? Every new piece of paper I feed through makes it as far as the drum.

[Iowatech]

Re: GR3770 - Hook lever not engaging pressure lever

Well, there might be a jam in that area somewhere. Shine a flashlight into the machine from the paper supply side of the machine and check if there is anything there. Depending on the machine's print count it could be a good idea to make sure the mylar guide is OK while doing that.
Maybe after removing the drum from the machine, shoot a good blast of air in through the feed guides as well, I wouldn't be surprised if a build up of paper dust was affecting the sensors in that area too. That's where the signal is generated to activate the pressure hook solenoid.
Speaking of the machine's print count, is there any chance you could let us know that machine's print or copy count? I still have a sneaking suspicion the solenoid's wiring is the culprit, but the GR3770 improved the structural integrity of the wiring over previous versions of that chassis, so there's a very good chance I am wrong and worthy of mocking if the count is too low. Thanks!

[Fayez Butts]

Re: GR3770 - Hook lever not engaging pressure lever

Well, there might be a jam in that area somewhere. Shine a flashlight into the machine from the paper supply side of the machine and check if there is anything there. Depending on the machine's print count it could be a good idea to make sure the mylar guide is OK while doing that.
Maybe after removing the drum from the machine, shoot a good blast of air in through the feed guides as well, I wouldn't be surprised if a build up of paper dust was affecting the sensors in that area too. That's where the signal is generated to activate the pressure hook solenoid.
Speaking of the machine's print count, is there any chance you could let us know that machine's print or copy count? I still have a sneaking suspicion the solenoid's wiring is the culprit, but the GR3770 improved the structural integrity of the wiring over previous versions of that chassis, so there's a very good chance I am wrong and worthy of mocking if the count is too low. Thanks!

Copies are at 2,775,628. Mylar guide looks alright, not crumpled or ripped. I hit that in-feed area with some compressed air and some dust came out but honestly I couldn't really see much, or even really an easy way in further.

[Fayez Butts]

Re: GR3770 - Hook lever not engaging pressure lever

Little update for you guys sitting on the edge of your seats - It's fixed! It was a timing issue. The P Disk was off timed by about 180 degrees, and I think it was a bad drum that got stuck.

[Fayez Butts]

Re: GR3770 - Hook lever not engaging pressure lever

Um, saga's not over yet actually guys. Is this normal?



What about this? Hasn't happened to me before, the whole panel just went dark and the machine is completely unresponsive until I turn it off and back on. This happened right in the middle of printing.

[Iowatech]

Re: GR3770 - Hook lever not engaging pressure lever

Well, the first picture in your last post isn't normal, because to the best of my knowledge that brown stuff under the power supply board couldn't be part of the machine.
I couldn't get a close enough look to be sure, but that kind of looks similar to "Chex Mix", a fun party snack. Though if that's the case I'd imagine the stuff in the picture has expired, or at least it is pretty stale.
As far as the blank screen goes, check the connections on the main board to make sure they are seated correctly. There's a surprisingly small difference between a fully seated connector and one that is not.
Maybe check the connectors in the control panel too.
And I suppose a code 90 wouldn't hurt.

[Iowatech]

Re: GR3770 - Hook lever not engaging pressure lever

Actually, if that brown stuff does turn out to have been previously edible food, that would tend to indicate that at some time there was a critter living in the back of that machine. So you may want to closely inspect all the wiring in the back of the machine, because critters are known to chew on the insulation.

[Fayez Butts]

Re: GR3770 - Hook lever not engaging pressure lever

Well, the first picture in your last post isn't normal, because to the best of my knowledge that brown stuff under the power supply board couldn't be part of the machine.
I couldn't get a close enough look to be sure, but that kind of looks similar to "Chex Mix", a fun party snack. Though if that's the case I'd imagine the stuff in the picture has expired, or at least it is pretty stale.
As far as the blank screen goes, check the connections on the main board to make sure they are seated correctly. There's a surprisingly small difference between a fully seated connector and one that is not.
Maybe check the connectors in the control panel too.
And I suppose a code 90 wouldn't hurt.

Thanks for the speedy reply! It is indeed Chex, but they're, like, whole. Not chewed on at all. It's weird. Maybe the previous owner's repair guy had a grudge? As for the wiring, it's definitely plausible that something came loose. I disconnected some wires when retiming the machine but they looked pretty good when I checked again this morning. Didn't get a chance to verify anything though, so I'll do a more thorough inspection and check code 90 this evening.

[hader1967]

Re: GR3770 - Hook lever not engaging pressure lever

Hi Fayez there is new GR Series Hook And Lever Assembly has been Changed in Pressure Area
I send you the Attachment file Explain That New GR Pressure Area.PDF