AARRGGHH! My first serious clog.

[PeterAit]

My 7900 has been chugging along for 7 years now without a serious clog. That is, one that could not be cleared by the standard "gentle" cleaning. Now things have changed. One channel (very light magenta if that matters) and two heavy-duty cleanings have not fixed it. Any advice?

[Paul_Roark]

I have found https://americaninkjetsystems.com/product/inkjet-cleaning-fluid-clf007p/ to be a good solution.

Paul
www.PaulRoark.com

[tonysiciliano1]

Not sure which brand printer a 7900 is, but you should try a manual clean of the print head. If you google it you will find many videos which show how to do it. Basically, you figure out how to unlock the print head, then you place a folded paper towel soaked in a cleaning solution on the track, then slide the print head over the paper towel and let it sit overnight. Then you move the print head left and right over the paper to scrub it gently, then remove it.

[Slobodan Blagojevic]

... two heavy-duty cleanings have not fixed it. Any advice?

I had to have 2-3 regular cleanings, plus 3-4 deep cleaning cycles to unclog a few remaining clogged nozzles on my Canon Pixma PRO-10. Since each cleaning uses ink, deep cleaning even more, I replaced original ink tanks with a non-canon brand (at 1/6th of the price) for that purpose.

[Richard.Wills]

Piezoflush from inkjet mall.
1st try, flood the capping station, and let the print head sit over night. Purge print, repeat.
2: If no joy, then refillable cart with piezo flush in VLM slot. Print a lot of light magenta colour, to try to bring the Piezo flush through
3 goto 1

Inkjet mall have good videos on the maintenance side.
If still no joy, then time for a dedicated Piezography B&W printer

[mcbroomf]

Although I would also recommend the manual head clean then the piezo flush as above I tried both techniques on my Epson SC8000 and nothing worked so I had to get the head replaced.

One other thing NOT to do is a bunch of head cleans one after another.  Not supposed to be good for the head.

[sportmaster]

Once upon a time I had four Epson 4900 printers, same series as your 7900. Image quality was great, but I spent more time clearing clogs than printing.  I tried every cleaning procedure I could find with varying degrees of success.  Clogs could cleaned for a while but eventually always returned. 

Later, I had a Epson 5000 and it seemed more clog resistant.

I eventually gave up and moved to HP with replaceable heads.

[George Marinos]

Before spending money it is a good idea if you send to the forum a magnified nozzle check to be evaluated.

[langier]

A year ago after too many cleanings and clogs still happening. I tried soaked rags, multiple cleanings, etc. but it was no use. I bit the bullet and had the head replaced on my 9900 by my independent Epson guru. For my printer, it was mail Magenta that was always an issue though other colors also would clog on a regular basis.

It was faster/easier/cheaper to replace the head then to find a replacement 9900 plus the hassles of disposal of such a large and heavy beast. Since the head was replaced (a new part number and a new head design), fewer cleanings have been needed and there is now no issues after a year. I certainly got my $$ out of the past ten years with this second-hand printer and should be good for another half-dozen years or so with the new head.

Heads are expensive and take a tech but for me was totally worthwhile.