GR 3750 Remove Jammed Master Disposal Unit problem

[jay-oh]

Hello,

I inserted a drum into my machine and tried to make a master.
It came up with an error. It first asked me to re-insert the master roll, which I did. But I could see that the old master is stuck and seems to have not fed/ejected into the Master Disposal Unit. The edge of the old master is around where the new master edge is trimmed. I tried pulling at it but it just rips.

Then when I closed the lid the following error appeared: "Remove Jammed Master Disposal Unit"

I ensured that there is nothing in the Master Disposal Unit. I re-inserted it and I have the same problem. I think I need to remove the drum and pull the old master away from underneath, as I'm guessing this is what is causing the error. However the drum green light is not illuminated – I cannot remove the drum.

I found a response relating to the same issue from the below link:
Remove Jammed Master in Disposal Unit

The person says: "You will have to turn the drum back a little bit manually and then press the green button again."

I don't know how to manually turn the drum back. Can anyone please tell me how to do this, or if they have any further advice?

Thank you!

[Iowatech]

If you open the scanner like you were going to replace the master roll, you will see the drum in the middle of the machine.
If the master clamp plate is caught in the vertical transport rollers, you'll need to rotate the drum clockwise until you can rotate the clamp plate to the open position. Then you should be able to get the drum out by closing the scanner and pressing the green button.
If the clamp plate did get caught in the master disposal area, your machine is probably out of time, which will cause the margins of what you copy to be off, probably by quite a bit. So you will probably need to retime the machine.
Finally, if you do choose to rotate the drum by hand, be extra careful. Some of the metal parts can have very sharp edges. Back in the day when the GR line wasn't obsolete, I used to have a package of small bandages in my tool kit for just such a job.

[jay-oh]

Thanks for your advice!
I manually rotated the drum so the clamp plate is at the top. I closed the scanner door, and pressed the green drum release button, it made the usual sounds, but the green light did not become active and a T1 service error comes up on screen. I can't get the drum out.
Any further advice?

Thank you!

[jay-oh]

To further clarify:
The initial error message, "Remove Jammed Master Disposal Unit" is no longer showing. However whenever I activate any function, including: drum release green button, make master or print, the T1 service error appears.

Another thing: prior to this drum getting stuck, I was using another drum. When using the other drum there was an undesired 50mm margin at the top of the printed page. So I pressume this was caused by the timing being out. Could the wrong timing have caused this new problem I'm having?

thank you!

[Iowatech]

T1 is a main motor lock error, which means the master clamp plate got caught in the disposal area again, most likely because you didn't rotate the clamp plate to the open position before you pressed the green button. The master clamp plate got bent the first time it got stuck in the disposal area or the master removal hooks are now out of position, and the clamp plate will continue to get stuck in the disposal area when you press the green until you rotate it to the open position.
On a lighter note, before you pressed the green button, was it lit up? If you rotate the drum until the green button is lit, the drum will come right out. No need to press the button.
The machine timing being off causing this problem is nothing I've ever seen, but then again I don't think I've seen a machine that was out of time as much as yours is that didn't jam every print. If my metric conversion is working, margins on the out of time machines I saw back in the day were usually off by less than 13mm.

[jay-oh]

T1 is a main motor lock error, which means the master clamp plate got caught in the disposal area again, most likely because you didn't rotate the clamp plate to the open position before you pressed the green button. The master clamp plate got bent the first time it got stuck in the disposal area or the master removal hooks are now out of position, and the clamp plate will continue to get stuck in the disposal area when you press the green until you rotate it to the open position.
On a lighter note, before you pressed the green button, was it lit up? If you rotate the drum until the green button is lit, the drum will come right out. No need to press the button.

That doesn't sound good. The clamp plate was already open, I'm pretty sure. I think the T1 service error may have been happening beforehand though, so maybe that's why.

The green button was not lit up before I pressed it. It didn't turn on (as far as I could tell) when the drum was rotated until the clamp plate was at the top.

After the T1 service error, when I open the scanner table, the screen mesh is at the top and I have to manually rotate the drum quite a distance before the clamp plate gets to the top again. I don't know if that information helps.

What you're describing about the master clamp plate being bent and the master removal hooks being out of position ... would this be damage to the machine or the drum?
I can probably write off this drum. But then, is it difficult to fix the machine & correct the timing etc.?

As you can probably tell, I am not a technician ... I am trying to learn how to fix this machine myself because the people that service Risos in Melbourne wont look at a machine this old :-(

Is it possible to explain how to resolve this Main Motor Lock Error problem? I read somewhere that there is a manual drum release under the cover at the back of the machine, near the power supply.

Thanks so much for your kind assistance. I truly appreciate it :-)

[Iowatech]

That doesn't sound good. The clamp plate was already open, I'm pretty sure. I think the T1 service error may have been happening beforehand though, so maybe that's why.

The green button was not lit up before I pressed it. It didn't turn on (as far as I could tell) when the drum was rotated until the clamp plate was at the top.

After the T1 service error, when I open the scanner table, the screen mesh is at the top and I have to manually rotate the drum quite a distance before the clamp plate gets to the top again. I don't know if that information helps.

What you're describing about the master clamp plate being bent and the master removal hooks being out of position ... would this be damage to the machine or the drum?
I can probably write off this drum. But then, is it difficult to fix the machine & correct the timing etc.?

As you can probably tell, I am not a technician ... I am trying to learn how to fix this machine myself because the people that service Risos in Melbourne wont look at a machine this old :-(

Is it possible to explain how to resolve this Main Motor Lock Error problem? I read somewhere that there is a manual drum release under the cover at the back of the machine, near the power supply.

Thanks so much for your kind assistance. I truly appreciate it :-)

The manual drum release for this machine is in the front of the machine, underneath the drum behind a rectangular metal cover with a slot cut into it. If you look carefully through the slot, you will see a silver hook that you will need to move, to the right I think, but I'm not sure as it has been years since I had to do that. But don't try that unless you are sure the drum is in the correct position to be removed, as otherwise the drum will only come out partially and then become stuck in the machine.
While not being able to see the machine makes this a little "iffy", I think it is kind of likely that the master clamp plate is bent on that drum. So that particular drum is probably at least the original offending part.
If it is not caused by the drum being unable to rotate freely, you should be able to reset the T1 error code by pressing the "Reset" key on the right hand side of the operator panel. I suppose if there were storms or nearby construction or something else that interfered with the local power utility recently there could have been a power surge that caused the error code, so if pressing the reset key doesn't work you might try holding down the reset key for a bit while turning the machine on. But only try those once.
You might also want to pull the front right hand cover off the machine and see if there are any blown fuses on that circuit board, just make sure to unplug the machine first. If you find a blown fuse, make sure to replace it with a fuse that has the same rating.
You might want to look into getting a service manual if you want to service the machine yourself. If you can't find one you might try Just Manuals, The Internet's largest selection of manuals ~ Instant Downloads , the manual is there and at a reasonable price.