Think Pump or boiler broken as water doesn't flow through

Hi just a tip from experience, grind the coffee fine and keep the spout ( where the coffee comes out) very near the cup, while making the coffee.
Kolbrun

This means the water cannot flow through the machine. Normal fix is to prime the machine (turn water dispenser on, fill a cup) or descale the machine. Go through the menu, select descale, enter, then turn the steam knob fully anti-clockwise. You should put the descaling solution in the water tank first.
If you have the auto-descale in the menu then run it. Run the solution through the machine twice. Then rinse well.

Does the pump work? The steam and hot water are from the boiler pressure, but the coffee water circuit is separate and needs the pump.
Does the three way solenoid valve click when you try for coffee?
Why did you change the control box, what was the original fault?

Clean the chamber below the white plastic valve, there is also a small discharge that leads from there into the drain tray clean that hole also.
Second the thermostat that controls the steam may be damaged or the cpu board, the contact the controls the steam may be damaged, i have seen both of those happen on some units.

Check the connection to the boiler from the pump, there is no water going to the boiler. Try this test, remove the brew unit you will see a white plastic valve behind it, carefully lift the small lever on the valve(HOT WATER), if water sprays, then the problen is at the brew unit, if no water then the boiler inlet or outlet is clogged.

If the pump vibrates when trying to draw water then that is a good sign. Remo;ve the hose on the output side of the pump and turn it on to see if it draws water(BE Careful water and electricity love each other too much), it water flows out the output side, reconnect to boiler and test. If that did not solve the no draw problem then the machine is blocked either at the boiler.

Hi
You may have a flow meter that is bad. If its white plastic check for corrosion at the wire terminals. If your have corrosion change the meter and you should be good to go.

If you could brewer coffee or get hot water out of the steam wand then it could be the one way valve on the bottom of the water tank. If you are running the pump output into a glass then it is probably scaled up in the boiler.

Well, I have little exposure to Saeco, but a lot to commercial coffee machines.
Saeco have a lot of custom made components, although these can be purchased, nothing is cheap! Neither is their repair service!
First, is the boiler heating?? If so:
No hot water/ no steam suggests a blockage. Assuming you can hear the pump working when attempting to do a coffee, you will probably find the water flowing back into the water tank via the relief valve. Of course, this valve itself could be the problem, or the pump failing to work through a blocked inlet filter or other problem.
Look now at the group head. Ever cleaned it? The filter and spray block should be removable, do so and clean them carefully. While you have them out, see whether water reaches the head by "making a coffee" into a cup placed under the head. BE CAREFUL OF SCALDING. If water now flows, cleaning the screen and spray block should restore operation.
Beyond that, it's inside the machine! There is a 3- way valve that operates when making a coffee. This can become clogged with coffee. There is another valve to open the steam.
If, like Saecos I have worked on, the boiler does both the hot water and the steam one at a time, look for problems BEFORE the boiler.
Hoe this helps a little....

Try draining the machine. Page 37 of the user manual, Drainage. Place cup under the steam/hot water tube, turn knob clockwise around to 9. If the pump is ok, it will start automatically and start filling the cup. Drain about 1/2 cup of hot water and return knob counterclockwise to start position. If the flow meter is not damaged, the Ventilate message should be gone.