What follows started back on 9 December. I've been fairly busy lately, having little time to make a posting here. As usual, I kept records to make catching up a little easier. This posting covers a number of days, so it's fairly long.
My 7900 had been idle for just a day shy of four weeks. This isn't typical, but such long periods without printing have happened several times during my ownership of the machine. On 9 Dec I had a job to make a single print for a client. I'd print on 24-inch roll Epson Luster. After sizing and optimizing the file in Photoshop I moved to the printer to start, as usual, with a nozzle check print. This print showed gaps in five channels, more than I'd ever seen at one time. Also for the first time ever, there was a tiny gap in the orange channel. Circumstances and environment were as usual; no extremes of temperature or humidity. A number of my ink cartridges were at 1%, and had been for some time. I had spares on hand for all.
OK, this wasn't going to be a simple "check and go" print job. I found gaps in C, O, LC, VM, and LLK. I felt the image file, being a little unusual and a challenge to properly sharpen, would need a test print, a slice through an area of high detail. I had no concerns about color fidelity in this test strip, so despite the failed nozzle check I printed the strip, learned what I needed to learn, and made appropriate adjustments to the file. The test strip color was awful, as you might expect. But having pumped some ink through the system I thought some of the channels might have cleared; stranger things have happened during my life with this 7900.
I ran another nozzle check, and thing had indeed changed. I still had the same gaps in C, O, and VM. But now LC was missing entirely, and about half of LLK had disappeared. I replaced all of the 1% inks with fuller cartridges, and then ran "powerful" cleanings of the C/VM pair, the LC/VLM pair, and the Y/LLK pair. It's been widely reported that powerful cleanings are hard on the printhead, so I left several minutes cooling time between those pair cleanings. When the last had finished I made another nozzle check print.
This time, I had more gaps in C, the gap in O remained (not a surprise, since it hadn't been cleaned), and LC was mostly back but still had a small gap. As I was still tweaking the image a bit I ran another test print, this time a small version of the full image. The top 2/3 of that print looked good, but the bottom third exhibited very obvious banding. Another nozzle check print (#4, if you're counting) showed a large area of gaps in C, the small gap in O, and numerous small gaps in LC, VM, LLK, and VLM. Today, the machine is chasing itself all over the place.
I repeated the powerful cleaning of the C/VM pair, the LC/VLM pair, and the Y/LLK pair, again leaving some time between each pair. The next nozzle check showed only the small gap in O, the one channel I'd not yet cleaned. After a standard cleaning of the O/G pair, the nozzle check (#6) showed perfect patterns in all channels.
Finally, I made the print. It was perfect. Being the only print I needed, I put the 1% inks back in the machine and quit for the day. I can't say how much ink the cleanings consumed. The waste ink tank went from 66% down to 58%. That one print turned out to be rather costly to make.
On 11 December I woke the printer and made a nozzle check, finding no problems. I made a small print.
On 14 December I needed to make a large print on HPN, which required switching to MK, something I'd not done in many months. I made the PK-to-MK swap, ran a nozzle check, and found a small gap in MK. That ink, at 1%, required replacing with a new cartridge so I could do the cleaning cycle. I did a standard cleaning of the MK/LK pair, which solved the problem without creating any new ones. I returned the 1% MK cartridge to the printer and made my print, which is very nice. HPN is such a lovely paper. I should do more with it.
Three days later I started the machine, did a nozzle check, found no problems, and then made 28 small prints on sheets of Epson Ultra Premium Presentation Paper (formerly Enhanced Matte). The prints were perfect. Another three days later I made a few more prints on the same paper for the same client, again without problems.
Finally, to wrap up, the next day (21 December) I made six more prints on the same paper for the same client, who'd come to pick up all the work I'd done for him this month, plus one large print on Epson Luster I'd made in early November.
Once again all of this points to the need to run these machines regularly. I can't explain why I had such problems after the four-week idle period, when there have been several periods over the years of that duration or longer with no or fewer or easier-to-resolve problems.
That's Life With a 7900.
--Jay
