Risograph GR 3770 color drum pump issue?

[Guest]

Hello there,

i recently bought a used blue color drum for my GR 3770. Now i tried to change the color into yellow, because i already have a blue one. I followed the instructions in this post: how to clean a drum roll

Everything worked fine until i loaded the drum with a new yellow cartridge.
I run several 100 copies in test mode 107 but when i'm looking inside the drum there is no yellow ink at all. Is it possible that the pump inside the drum is not working?
Maybe it's the wrong cartridge? On the package is written "RP/RN ink" (S-3259) but "usable for rc/ra/gr/fr".

Thanks for your help!

[bigste]

I have a couple of your GR's and have never used RP/RN inks in them. If it fits and clicks into place it should be ok. Is the switch lug the same on the end of the ink cartridge? Sounds like it's not pumping. I've had cases of the pump having an airlock and needing priming but other than that I cannot offer any more advice.

[ddude]

Color ink tubes should be able to cross from RP to GR/FR. If the tube was incorrect, you should get a code. Is the test master real dark? The drum will not pull in new ink until the supply inside the drum is depleted. You may have an air bubble in the pump system, I'm not sure how to push that out. It may take several 100s of dark impressions before you begin to notice a change, you should get green copies soon, before yellow, as the blue ink worlks itself out.

[RRodgers]

it takes a LONG time to get new ink to cycle into a drum. Run SERVERAL prints to get the old ink out. And when I say serveral I mean hundreds.

[joelsa12]

run test mode 101 to pump up the drum if you run it and can not here the motor running inside of the drum it could be bad. sometimes while running tm 101 you have to push on the plunger inside the tube to get the ink to seat and the air in the pump to get out.

[joelsa12]

p.s. color inks normally work in all machines. unless you go to the MZ RZ series which have an RF tag. The color ink will work!

[Prima]

Thanks everyone! I run test mode 101 like joelsa12 said, and it worked out. The drum pumped a lot of ink inside and now i get some nice greenish copies.

By the way: is there any directory of test modes in the internet? I couldn't find anything.

[joelsa12]

i am sure there are many places where you can get a tech manual for this machine. it all comes from memory from me. i would bet i have worked on thousands of Riso's. Paul are you out there?? if you check the manual postings and look for manuals for you. there will be a link to his website and i think he has a GR manual. i would send you one if i had it, but like i said it comes from memory.