wrong drum size

[risomat]

[risomat]

[ddude]

Strange- GR(w) drums should work just fine in a GR3770, I think that the black drum would be a problem, due to the HD ink in the black, but color (w) drums should be interchangeable.

[risomat]

[ddude]

Yes, since paper size is different, the problem may be a switch setting. If you have a working color drum, remove the front cover and look at the bank of switches on the drum board- make the non-working drum switches match the working drum, you should be okay.

[bigste]

A GR colour drum will fit the 3770 but the black one won't unless you change the dip switches on the drums setting card. I would guess your problem lies with that card or the wiring to it. I had similar problems in the past. As it is same for 2 drums if they are both colour drums it could be the plug and socket that connect the drum to the riso.

[risomat]

gotcha!
thanks ddude, changing the switch setting helped.

color (w) drum setting (us): R8 off, R9 off, R10 on, R11 off, R12 on, R13 off
color (w) drum setting (europe): R8 off, R9 off, R10 off, R11 off, R12 on, R13 off
black (w) drum setting (europe): R8 off, R9 off, R10 off, R11 off, R12 off, R13 on