The yellow should have been carried out. So you can either try and purge it out with a custom QTR Calibration Mode target by expanding the yellow 100% square to cover the entire image and repeatedly printing it in Calibration mode. Or you can do another Initial INK CHARGE which will waste ink in all the positions.
In QuadToneRIP / CurveDesign / Images open inkseparation8.tif in Photoshop.
It does not have an embedded profile - so if your Photoshop is setup correctly you should get a dialogue warning you of this.
You must select "Leave as is (Don't Color Manage)
Then outline within the Yellow 100% square with the rectangle selection tool and select Edit / Transform / Scale and scale the selection to cover the entire image area.
Then Save As inkseparationYellow.tif and DO NOT EMBED a profile.
Put QTR in Calibration Mode when you print this image.
It will trigger only the Yellow position to print on an entire page.
Print until the yellow disappears....