Epson 3800 Magenta chanel problem


I have an Epson pro 3800, with printhead problem.

Some leak with the black photo cartridge and many nozzles glocked.

I have change the dampers and the first one is solved.

But the Magenta chanel have many (25-30) nozzles glocked. All other chanel are cleaning.

I have loaded magenta cartridge with Piezo and made many cleaning cycle but the problemi is not solved.

I have tried also with syringe charged with ammonia (30-50%) + distilled water, but also with this procedure the problem is not solved.

What can I do?

Use an ultrasonic washed machine?

Use Isopropyl alcool in 30-40%