All the lights are flashing on my Braun Tassimo TA1200 and will not make coffee

Several possibilities: (1) No water in tank.
(2) Tank not inserted properly. Try removing tank and then replacing it, making sure that the hook-tab at the back of the tassimo body engages the matching slot at the front of the tank.
(3) Tank not seated properly. Try pressing down on the tank and twisting left or right. If this stops the blinking and allows your drink to brew, at least you know where the problem is. If you have to do this all the time, consider exchanging the unit.
(4) The lights will all also blink if there is residue (coffee, milk, etc) on the bar code reader window. The residue is usually plainly visible. The bar code reader window is a horizontal rectangel directly under where the bar code of the T-Disc sits in the Tassimo. To fix this, just wipe the window clean (no need to scrub), close the lid again and check for blinking.

I had this problem, all lights flashing and nothing happening. Although the float in the water tank seemed OK popping up and down, I took it out and broke it open to find the magnet had corroded due to water leaking in. I placed one of my kids' magnets over the part of the machine that lined up with where the float would be and the lights stopped flashing! So I took a hammer to the magnet so I had just a small piece and wedged it in between the water tank and machine. Works perfect now. You could fashion something else or replace the float if you can get hold of one but this way works fine. I refill my tank using a jug so I don't have to fiddle about with the magnet when trying to put the tank back.

Tassimo coffee t disc was put in improper & coffee went everywhere now my machine wont work