How to unblock the straw of the print head of the IMAJE 9040 inkjet printer?

After unblocking the ink supply, cleaning and recycling tubes, the pipe in the front part of the nozzle is cleared, and then we unblock the straws:

There are two valves on the side of the straw, one is the cleaning valve, the other is the ink supply valve. There are straw on the back or in the front of it. We should make sure that the straw is open. If it is not smooth, we also need to remove the two pipes behind the solenoid valve.

Before dismantling, we can dismantle the solenoid valve. Before dismantling the solenoid valve, we must spray some cleaning fluid, and then pry it up:

Then pry up another solenoid valve:

After prying up all the solenoid valves, we can test whether the pipe is unblocked.

It's the same. Use the ear ball to suck some detergent, then insert it into one end of the cleaning tube, and then blow hard:

Then, cleaning fluid will come out at the rear end of the solenoid valve, which means that the straw is unblocked:

Then insert it into one end of the ink supply pipe, and the cleaning solution will come out after blowing, indicating that the suction pipe is also unobstructed:

Then let's see if the two pipes at the front end of the solenoid valve, all the way to the nozzle, are unblocked.

We can clamp these two straws with pointed nose pliers and pull them out.

Pull out the ink supply pipe:

After pulling out, we blow air from one end of the ink supply pipe, and then see if there will be cleaning fluid coming out of the front end of the solenoid valve. If there is, it means that the pipe is unblocked:

Then pull out the cleaning pipe, gently, and then use the ear ball to suck the cleaning solution to blow. If there is solvent coming out of the front end of the solenoid valve, it means that it is unblocked:

The cleaning tube is not smooth. There is a throttle tube in it. We need to remove it and clean it with ultrasonic wave:

We look at the valve and poke it through the front end of the solenoid valve with steel wire to see if it has spring like elasticity:

These two valves have no elasticity and are stuck by ink. We remove the blocked solenoid valve. There are three wires behind each solenoid valve. We need to remove it with a soldering iron:

Then put the solenoid valve into a bottle, put some detergent in the bottle, close the lid, shake it, and let it stand for half an hour to one hour. Then we can see if it is unblocked. If it is unblocked, we can install the valve: