Why does it brew weak coffee?

What you see in the waste tank dry coffe powder?

It seems that for whatever reason not enough grounds are being produced to make the correct size puck of coffee for brewing. You need to investigate what quantity of grounds is being produced and find a way to increase it.

They only know that the beans is empty when it comes to compressing the grounds into a puck just before brewing. If the brew unit has nothing in the chamber to compress then it assumes you are out of beans.. Remove and thoroughly clean the brew unit and make sure grounds are exiting the grinder when the grinder is running.

Syntia is not set to "3 beans" amount or beans used are too large to create enough grounds to make a full 9 grams for a good puck .
The finger guard does not allow enough beans to grind in the timing of the software , common problem.... until the finger guard openings are made bigger or ... the software is re-programmed

You have accidentally turned down the brew strength selector, on front of unit just above "clean" and "descale" buttons. Dial it the the maximum. Will grind longer, make more grounds, larger puck, stronger coffee. Or this dial is broken/ wire broken etc. u can disassemble per some other posts on here and check wire connections. I did all that then realized someone had just turned it down. So I turned it to maximum strength and problem fixed.

The only answer is more coffee...more...more

have you tried adjust coffee strenght?
This is the bean symbol on the bottom of the front control

d-hound same problem spoke to tech re 4070 they say it is just gring amount and beans and grind they are wrong made great coffee 30 days now **** water please call Randy 484-695-2450 or [email protected]

I think I have the answer to this: when mine started doing the same thing, I found that coffee grounds had accumulated and were blocking the seal of the water supply with the brew-group.
The Behind the brew-group is a clear tube with o-rings that slides into the brew group to supply water. One or both of these is clogged with accumulated coffee grounds. Try cleaning out both well.
-tony

You say " I am getting a weak brew because of not being able to adust the grind to more coarse with the adjustment knob in the bean hopper" By making it more coarse you are making it weaker. Unless you just wrote it wrong. To make it stronger you should lower the grinder number to a smaller number. Usually about 4-6. Be sure you have the grinder grinding when you move it to a lower number. The pump noise could be that in shipping your pump came loose from it's mount. Nothing you can do without sending it to a Authorized Saeco Repair shop.