Frustrating Issue Epson 4900 Printer

[beauport]

I'm hopeful I may find some help for my Epson 4900. I use the 4900 and an Epson 3880
 regularly and out of the blue the prints from the 4900 appear slightly washed out and
 have a "cooler" look to them than what I am seeing on my calibrated monitor.
 I printed the same image on the 3880 on the same paper type and the print matched
 very closely to what the monitor displayed. I did all the usual things to correct the issue
 on the 4900, head cleaning, verifying no clogging to find there were two clogged heads but
 with subsequent cleaning all are now clean. I did a head alignment. At the end the results
 were the same. I called Epson professional imaging and the rep suggested I uninstall and
 reinstall the print drivers which I did. I made sure the drivers and firmware are up to date.
 I've been printing with Epson Exhibition Fiber paper and, to save money while getting poor
 prints I tried Red River polar luster. Again, the images printed on the 3880 were good
 while those printed on the 4900 were slightly washed out and cool.
 Let me add, while the printer says there are no head clogs, when I print the pattern out
 all the color patterns look fine except the yellow has no lines running through it, just the
 block of yellow. Calling Epson help about this the rep said this was normal. This seems
 odd to me as I've never heard of this nor have I seen documentation that the yellow
 should be any different than the other colors.
 Photoshop CS6 for file prep and printing. Using a PC with Windows 7, 64 bit.
 Up until 2 days ago both printers made nearly identical prints. I'm not sure what to try next.
 Any suggestions will be greatly appreciated, thanks!
Andy

[Christoph C. Feldhaim]

You don't happen to accidentally have changed to wrong profiles for your 4900 and your paper?
Could you post a Macro shot of the nozzle check which bothers you so much ?

[Some Guy]

Does sound like a clogged yellow if you have missing lines showing in the nozzle check.  Explains the coolness and washed out appearance too.

SG

[beauport]

I took a close up of the printed pattern and under close scrutiny, which my eyes with my reading glasses couldn't see, there are lines in the yellow pattern.  I'm attaching a photo of a portion of the entire pattern.  The blur toward the bottom of the pattern is most likely me and the lens not being parallel to the paper. 
So, if the yellow head isn't clogged, and nor are the other heads, I'm now really perplexed.

[Christoph C. Feldhaim]

I took a close up of the printed pattern and under close scrutiny, which my eyes with my reading glasses couldn't see, there are lines in the yellow pattern.  I'm attaching a photo of a portion of the entire pattern.  The blur toward the bottom of the pattern is most likely me and the lens not being parallel to the paper.  
So, if the yellow head isn't clogged, and nor are the other heads, I'm now really perplexed.

Thats why I asked - yellow is very hard to see.
Are you 100% sure about your profiles?
Your papers?
Some accidental change in some printer driver setting?
Sometimes it's a most idiotic thing you never think of.

[BrianWJH]

I use the 4900 and an Epson 3880  regularly and out of the blue the prints from the 4900 appear slightly washed out and have a "cooler" look to them than what I am seeing on my calibrated monitor.

Is the 4900 print washed out on the whole print, does the start of the print exhibit this problem?

I'm wondering if the ink damper is clogged and doing a nozzle check takes a very small amount of ink which the clogged damper can provide, however doing a print requires a larger and steady ink flow which a clogged damper may not reliably deliver.

Brian.

[beauport]

Is the 4900 print washed out on the whole print, does the start of the print exhibit this problem?

I'm wondering if the ink damper is clogged and doing a nozzle check takes a very small amount of ink which the clogged damper can provide, however doing a print requires a larger and steady ink flow which a clogged damper may not reliably deliver.

Brian.

The washed out look is on the entire print.  The washed out appearance seems to be lessenning though still noticeable, especially on skin tones.  I'm wondering if there was/is a clog and the clog is beginning to clear.  Is there such a thing as a partial clog?  I'm thinking of using some cheap paper and print a number of full color images to keep the ink moving through the heads.