HP L260-Keep losing magenta heads

[AKProbeGT]

We keep having issues with the magenta head(s) not printing correctly on our HP L260. Last week we noticed reds were not printing as dark as they should. We replaced both LM/M heads with units we had in stock that had been sitting around for a bit as I like to have them in stock but we really don't go through heads real fast. That fixed our problem and we were back up and running. On Monday we had the same problem again. On test plots the Magenta looked as light as the Light Magenta on both heads so we replaced both heads with new piece from Grimco. Again the problem was fixed till today. I printed maybe 50 feet of vinyl before the same issue returned. You can see in the attached picture what was red quickly turned to orange. I printed a test plot and again both Magenta's look light. These heads only have 17ml through them. Any suggestions on what could be wrong?

 

[Pauly]

If you put an older set of heads, do they stop working immediately or are they good for 10-15m of print before they die out again. if so, it probably isn't the heads. ink supply possibly.

 

[AKProbeGT]

If you put an older set of heads, do they stop working immediately or are they good for 10-15m of print before they die out again. if so, it probably isn't the heads. ink supply possibly.

I just put the heads we pulled out yesterday back in and I can't get them to print with any success. It seems once they "go bad" they won't print right again.

 

[AKProbeGT]

I tried turning on the gutter on in Onyx but that didn't solve my issue so I called HP. Turns out there are a batch of bad Magenta cartridges out there that are filled with Light Magenta ink. As soon as I told the tech on the phone he knew what the issue was. When you put new print heads in it prints ok for a little bit because there is ink that comes in the heads. Once that runs out you are getting Light Magenta ink out of the "Magenta" cartridge. These bad ink cartridges generally have an expiration date on the side of Feb or March 2019 though apparently not all cartridges in that range are bad.HP is sending new print heads to replace the ones we went through at no cost. They are also sending 2 new ink cartridges at no cost but because of this issue they are backordered through HP so I've also ordered through Grimco so we can get back up and running as soon as possible. HP is also sending a file that will print pure magenta because we need to clear the Magenta ink lines of Light Magenta ink. Hope to up and running again tomorrow.