The pressure pump does not turn on more often then necessary, usually only just when a job gets send to the printer.
Except for 3 a stubborn missing nozzles in Magenta, I had not experienced previous trouble with this printer. Gaps in M were the reason for the purchase of the first set of carts, and the printer was left a few month filled with piezo-flush. In the mean time I had decided to convert to a BW printer (with a remap of the M chanel) and ordered a second set of carts, which were filled with piezography ink last week.
Prior to this the printer only contained OEM Epson inks (although some out of date) and has seen less than 2000 prints.
The carts (two sets) are apparently identical to yours, one set was only filled with piezo-flush, the other only with piezography ink.
I also tend to favor the dead dampers hypothesis, caused by age and maybe old ink (that the piezography bath didn't resolve)
If the replacement parts are around US 150.- as you tell me, and that it takes at least 2-3 hours to install them, I am looking at a US$ 500.- repair, and that is hoping that the capping station is OK...
This is about the price here of a second hand printer (if you are lucky), or a new printer without the OEM inks I wouldn't need...
Your help is still very much appreciated !
And somewhat off-topic:
Regardless of the money invested, it is somewhat absurd;
I can fix anything on my 40 years old enlarger myself, even have parts remade by a mechanic, but I am lead by the manufacturer of a 20kg 3years old printer to trash it because a 10gr. fabric filter needs to be replaced, but isn't available as a part and costs as much as the whole machine to replace.
You do a great job by providing inks, refillable cartridges, resetters for waste tanks, expertise and support that manufacturers are reluctant to disclose. Sometimes promoting art is really a political statement...
Merry Christmas and happy new year !