RJ900C need help with service.

[sporgo]

I recently acquired a Mutoh RJ900c printer I am trying to resurrect from long storage.

The print head seems salvageable so I thought I would get some bulk ink carts and try to run a cleaning or test cycle. I was apalled to discover the unit demands oem carts that have chips on them or it wont do anything. I had grown used to my Epson and Brother units where I just pour in bulk ink and keep going.

Does anyone have info on how I can patch the firmware to bypass the machine asking for original carts? Or maybe an old version of MSA?

I tried to reach out to Mutoh but its an old machine so they completely ignored my inquries. This is basically the last hope before I dismantle and part it out.

 

[garyroy]

Part it out.

 

[Umca]

The printer does not have smartcards on the cartridges. Just optical recognition by label (mirror and black squares). You can made them very easy.

 

[sporgo]

The printer does not have smartcards on the cartridges. Just optical recognition by label (mirror and black squares). You can made them very easy.

Interesting. I did note that they looked more like optical pickups than smart card contact readers. Do you have instructions on how to make them?

 

[sporgo]

Part it out.

Do you need the parts lol. I paid practically nothing for it and I have a great deal of past experience repairing printers. Most of the large formats I looked at for sale near me are probably not fixable but the sellers are asking hundreds if not thousands anyway... If there was an Epson that fit my needs within 200 miles I would be all over it. I live in a fairly out of the way place. Buying new isn't an option at the moment because the roi would take far too long.

 

[sporgo]

So after doing a bunch of testing I found that the sensors in question only check ink levels. They do not inform the machine of the cartridge presence or ID. The RJ900c seems to rely on just some tiny white switches where the front of the cartridge loads and not any kind of cart ID system. I was able to tape down the switches in question and proceed to cleaning and maintenance cycles.

 

[sporgo]

Picture of the suspected ink level sensors. Varying the level of light that reaches these influences the printer reporting low ink levels.

 

[Umca]

No. It is ink ID board exactly.
The sticker on cartridge looks like mirror self-adhesive vinyl about 5x5 cm with black squares about 1x1 cm. The sensor detect reflection difference depends on square location and the printer accepts the cartridge.
Low ink sensor located under ink ID board.

 

[sporgo]

If that is the case then I can only assume the firmware was already bypassed at some point because I received no warning from the printer about non OEM cartridge. It just goes through the initial cleaning and paper check and then says "ready to plot".

 

[Umca]

Finally I found the picture...

 

[sporgo]

That seems to be a reflective sticker with a window in the sticker to monitor ink level.

 

[Solventinkjet]

That seems to be a reflective sticker with a window in the sticker to monitor ink level.

It's much simpler than that. The ink ID board is simply looking for that black box on the mirror sticker to verify it's a Mutoh cartridge. The ink level indicator is that little plastic tab that sticks out of the whole in the cartridge.

 

[sporgo]

Ok that is in line with what the guys on the electronics board thought. One side is looking for the reflection off the label and the other for no reflection thus the blacked out square. I would suspect they alternate the pattern for different carts but maybe not.

Either way my particular unit does not seem to be bothered by the lack of them. Its possible the previous owners had that turned off maybe to convert it to dye sub inks.

 

[Solventinkjet]

Ok that is in line with what the guys on the electronics board thought. One side is looking for the reflection off the label and the other for no reflection thus the blacked out square. I would suspect they alternate the pattern for different carts but maybe not.

Either way my particular unit does not seem to be bothered by the lack of them. Its possible the previous owners had that turned off maybe to convert it to dye sub inks.

The RJ-900 machines are used with so many different types of ink that it's one of Mutoh's least locked machines when it comes to ink.

 

[sporgo]

The RJ-900 machines are used with so many different types of ink that it's one of Mutoh's least locked machines when it comes to ink.

I'm glad to hear that. I have no desire to deal with any OEM ink cart situation ever again. Which is why I have an ecotank for most of my small prints.