Typewriter My typewriter it performs well, but will not print any letters.

If the printwheel isn't distorted or you aren't in KBII or a language mode the printwheel homing pawl is likely broken. You need a tech.

DickyO

Push down on both ends of the platen and see if it snaps back in place.

Sounds like the platen has worked loose. press down firmly on both ends of the platen (black rubber rol) it should snap back into place.

DckyO

check to see that when yu replace the ribbon it has not slipped in front of the print ribbon and that you have not got the button for corection pressed by mistake it is using this to print you letters not the ink ribbon

First make sure that the the pitch selector on the keyboard is set to the correct pitch for the printwheel , if there is a pitch selector on this typewriter. Also try taking out and reinstalling the printwheel then turn the typewriter off and back on so it can rehome the printwheel.

Typing wrong letters.
Please help immediately

Most likely the plastic cap on the print solenoid is broken they are available but are a bit tricky to install.

DickyO

Check the print wheel to see if any spokes are bent or missing, be sure that you have the proper correction tape (tack free) and that you are not in proportional space or have an international print wheel.

DickyO

The ML-300 needs to be reset each time the Daisy Wheel is removed or replaced or if the Keyboard Switch changes position. According to Brother, if this is not done the typewriter will print incorrect characters. Try these steps: 1) Open the Top Cover. There is a lever directly behind the Daisy Wheel. Pull the lever back towards you. Remove the Daisy Wheel by pulling it up and out. 2) Verify that it is the Standard Daisy Wheel that came with your machine and not a Symbol or International Daisey Wheel. Write down the Pitch (10, 12, or dual pitch 1012) printed on the wheel. 3) Reinstall the Daisy Wheel (the plastic top ear goes to your right.) Push the lever (step 1) forward. 4) Press the ALT key plus the PITCH key and the number 1 key simultaneously. Verify the Pitch setting is the same as is printed on the Daisy Wheel. 5) Press the CODE key plus the RESET key and the letter Q key simultaneously. This will reset the typewriter mechanism and align (or time, in technical terms) the carriage mechanism. Check if the typewriter prints correctly now. If still incorrect, perform these additional steps. 6) Verify the three position Keyboard Switch (inside the top cover, on the right side, at the bottom) is in the I=Standard position. The other positions are: II=International and III=Symbol. 7) If the Keyboard Switch is in the correct position, slide it to position III and then back to I. (This will clean the switch contacts in case they are dirty and not making good electrical contact. 8) Press the CODE key plus the RESET key and the letter Q key combination again to reset the typewriter mechanism. Check if the typewriter prints correctly now. If still incorrect, the only other things I can think of is that: 1) an incorrect Daisy Wheel is installed that does not work in the ML-300. Brother sell a "B type" Daisy Wheel with two plastic ridges/raised slots below the center of the Daisy Wheel (viewed with the raised top tab on your left.) The B type are incompatible with your machine. 2) the typewriter has failed and needs repair.

check to make sure the selection lever for pitch is not in the ps position and that the keyboard selector is in kb1 position