Really in need of suggestions I have run out of ideas.

Thanx for the advice HAT,
At this point in time I will try anything. I think I have left over 220/221 carts from my old mx860. I think there are some with the clear windows on the side. I will flush them and prep them by changing the chips. I am going to make a setup so I can top fill these by weight. I have some snap on orange clips I will use and tare them on the scale so I will be able to see how much ink Im putting in them both visually and by weight. I will also go back to using syringes for filling where I can control how much ink is going in. Squeeze bottles are good for German filling but very awkward to use when top filling as I found out yesterday. Im also going to break down and buy a new Magenta cart this afternoon to give it a try also.
I will report back as soon as I get this done......

OK, review the full process of what has gone on.
Printer was working perfectly and then is left for three weeks while it was left powered on and it is so clogged that soaking will not remove it. If the purge unit is fine, sitting in the park position should not cause this.
New printhead and something similar happens again. New OEM carts and the problem returns still

Then something is said that did not register but should have. "It almost seems as though letting the printer set for a few days or longer has something to do with it." My prognosis is that some switching circuits that control the nozzles are in fact "leaky". When the nozzle is not being used, there should be NO current going through. If in fact, there is a low level current, strong enough to continually heat the nozzle heaters BUT not large enough to cause firing, it will cause what is being experienced. Also consider it has happened on two printheads.

Do consider the events and the conditions surrounding it. Now this low level heating may not be enough to clog the printhead instantly BUT if the printer is used daily, the ink that has heated gets ejected before it becomes concentrated.

What the second printhead might be experiencing is now further early failure. What I would do is the following. Soak and flush the new printhead.
Get the printer working. Now each day or whenever it is not being used, remove the power completely. If the problem goes away, then it is a leaky control circuit.

I now believe a similar situation exists on printers that have "strange" clogging issues that do not make sense.

I know of three to four instances that this is highly suspected. What I do not know is whether simply powering off the printer will stop the leakage current or whether removal of the plug is required when this leakage is suspected.

Note the bottom bar on this image previously posted by @pearlhouse, especially the start of the missing stripes toward the left side. Assuming that these bars were printed in a single pass from left to right, doesn't this look like ink starvation?

Yes, it appears to be a starvation problem...

Would agree with the assessments above... Ink flow/starvation are prime candidates.

Something else to consider though and that's ink age and the effect of higher temps (something that's a bit of a current issue here) which may have tipped the balance into algae starting to grow.

Purchasing an OEM replacement cartridge is definitely a good way to discern whether the ink, refilling and/or cartridge are where to focus.

Ok guys here’s the latest. I still have the same problem. I agree it is ink starvation but only with the magenta color. Im pretty sure the problem is not the cartridges. I flushed an old set of 220/221 carts as HAT suggested and top refilled them. I also changed the chips to 226 and 225 chips. I will say top filling these suckers is a lot more work and messier than using the German method using squeeze bottles with 2” needles. I really don’t understand when comparing top fill to German fill how some of you are still sticking to the top fill method. (That’s my opinion and Im stickin to it.) But to try and solve this problem I am bending and going back to top filling (temporarily). Along with this set I have also tried 4 other 226 magenta cartridges. Two were recently flushed and had been German refilled twice. Two others were just flushed last week and top filled once only. All these cart were final prepped with pharmacists solution. Ive also tried 2 OEM carts that have NEVER been refilled. One of these had been used previously to check a print head that was plugged. The second one I just purchased on Saturday and tried it today. All produced the same results. Nozzle checks were printed for each and most came out perfect, a couple required a nozzle cleaning to get a good nozzle check printout. At one point Sat nite I thought I finally had something going. I installed one of the carts that I had flushed and top filled last week. Great nozzle check printout and then two different color printouts that came out perfect. A couple of hours later I tried the same two color printouts and I was back to square one. Both showed ink starvation in the magenta color areas. I have uploaded all four of these to one again show the problem.
Any other ideas on this ink starvation????
Im thinking maybe Mikling is on to something with the electronic breakdown of transistors. If this is true than I think he is saying my logic board is bad??? And then maybe burning up the printhead???.

mikling said:

OK, review the full process of what has gone on.
Printer was working perfectly and then is left for three weeks while it was left powered on and it is so clogged that soaking will not remove it. If the purge unit is fine, sitting in the park position should not cause this.
New printhead and something similar happens again. New OEM carts and the problem returns still

Then something is said that did not register but should have. "It almost seems as though letting the printer set for a few days or longer has something to do with it." My prognosis is that some switching circuits that control the nozzles are in fact "leaky". When the nozzle is not being used, there should be NO current going through. If in fact, there is a low level current, strong enough to continually heat the nozzle heaters BUT not large enough to cause firing, it will cause what is being experienced. Also consider it has happened on two printheads.

Do consider the events and the conditions surrounding it. Now this low level heating may not be enough to clog the printhead instantly BUT if the printer is used daily, the ink that has heated gets ejected before it becomes concentrated.

What the second printhead might be experiencing is now further early failure. What I would do is the following. Soak and flush the new printhead.
Get the printer working. Now each day or whenever it is not being used, remove the power completely. If the problem goes away, then it is a leaky control circuit.

.

Click to expand...

Not sure what you mean here.. "Get the printer working." ???? Do you mean get a good nozzle check printout and then turn it off????

In my opinion the uploaded test pictures show a typical case of ink starvation. As a new OEM cartridge makes no difference the problem is a print head problem.

If you are very lucky, the problem could be caused by the ink inlet gasket not being able to expand and compress freely to make a good seal due to leaked ink. So you could try to remove the gasket and clean it. You should also clean the part of the print head where the gasket is located.

If this brings no improvement the fine ink channels for magenta in the upper part of the print head are most likely clogged. The channels could be cleaned by forcing a cleaning fluid like Windex or pharmacists cleaning solution through the channels using a turkey baster or similar. Be careful, too much pressure might damage the print head, and loosened clogs might clog the nozzles instead. This is a risky operation.

Some might prefer to remove the nozzle plate from the print head by cutting the four plastic nibs that hold the circuit board and removing the two Phillips screws holding the ceramic nozzle plate. With the print head disassembled you can use much more force in trying to unclog the ink channels. This is a high risk operation, you risk not only ruining the print head but also the logic board making the printer a total loss.

Cleaning the ink channels is a risky operation, and I suggest to wait for comments or alternative suggestions before trying out the cleaning procedures, especially disassembling the print head.

I would put a couple of drops of pharmacist solution into the top of magenta cartridge and leave it to mix with the ink, and then remove the print head and leave it to soak in some warm water and washing up liquid for 24 hours then next day try run your nozzle prints again to see if the problem has finally ceased..

These procedures are just straight forward and non destructive in any way so can be done relatively easy, but please remember to thoroughly dry the print head before attempting to reinstall it again for safety reasons.

pearlhouse said:

Im thinking maybe Mikling is on to something with the electronic breakdown of transistors. If this is true than I think he is saying my logic board is bad??? And then maybe burning up the printhead???.

Click to expand...

If the transistors are blown, how do they work at the start of the nozzle check, then gradually drop out in that pattern? Only @mikling can answer where the transistors that he is discussing are located, but the individual transistors that fire each nozzle are located in the print head itself. The data for which nozzle(s) to fire comes over a serial data link from the main logic board to the print head.
If you decide to clean the upper part of the print head, here is a long thread on the subject. As is noted in the thread, only try this after you have given up on everything else, and have decided that the print head is toast. I have saved two print heads using this approach over the years. In each case, the PM channel became clogged - is the Magenta ink prone to some form of plateout or bacterial growth?