Our old but well maintained 250GT now has a strange printing issue. We had Canon replace the two yellow print heads recently and immediately had an issue where the yellow ink starts to drop out after printing about 20-25 cm of a full bed with heavy yellow coverage.
If you stop the print and do a nozzle check it is fine. Somehow the yellow printheads are getting ink starvation while printing?
We did notice that when the machine is idle the ink meniscus level on the popup ink screen fluctuates from 12.1 down to 10.7 and then back up to 12.1.
The Canon techs were in for several days trying to find a fix with no luck. Still waiting for a full service report as to what was checked/changed. More on that later.
What is interesting is that on the schematic of the ink and vacuum system for this printer all the plastic PTFE micro filters are specified to be the 0.2 micron version.
However, there are 0.2 micron filters on the black and cyan purge valves and 0.45 micron filters on the magenta and yellow purge valves. Also, the PTFE filters inside the cavity behind the black ink filters are also 0.45 micron.
Only the Canon techs have been in to change those filters over the years.
Does anyone know if it is critical that these all be the 0.2 micron filters? Could a possible vacuum imbalance cause this issue of ink starvation only on the yellow?
If you stop the print and do a nozzle check it is fine. Somehow the yellow printheads are getting ink starvation while printing?
We did notice that when the machine is idle the ink meniscus level on the popup ink screen fluctuates from 12.1 down to 10.7 and then back up to 12.1.
The Canon techs were in for several days trying to find a fix with no luck. Still waiting for a full service report as to what was checked/changed. More on that later.
What is interesting is that on the schematic of the ink and vacuum system for this printer all the plastic PTFE micro filters are specified to be the 0.2 micron version.
However, there are 0.2 micron filters on the black and cyan purge valves and 0.45 micron filters on the magenta and yellow purge valves. Also, the PTFE filters inside the cavity behind the black ink filters are also 0.45 micron.
Only the Canon techs have been in to change those filters over the years.
Does anyone know if it is critical that these all be the 0.2 micron filters? Could a possible vacuum imbalance cause this issue of ink starvation only on the yellow?