How to replace LCD on BMW 3-Series E90 E92 E93 Professional radio
1. First remove the heater control by pry open the left and right side.
2. Then remove the two screws that hold the radio.
3. Pull out the radio. Disconnect the left multi-plug by releasing the plastic retaining rod upward. Press the small TAB on the right side and carefully pull the connector from the back of the radio to remove the connector for the antenna cable.
4. Remove the two buttons on the front panel of the radio and pull them out of the device.
5. Loosen the indicating screw and remove the lid.
6. Remove the five screws on the left side. Carefully pull the radiator out.
7. The heat sink and three chips will have white thermal conductivity paste. This should be removed with alcohol or citrus hot paste remover. It is best to use a cloth to remove most of the paste, and then use a fine brush to remove the remaining paste, immersed in the solvent. The radio now looks like this.
8. Now remove the five screws holding the front panel together.
9. Tilt the top of the front panel away from the radio body. There is a plastic articulated clamshell on the connector shown. Open the cover and carefully pull the cable out of the connector to disconnect the ribbon cable.
10. Carefully disconnect the ribbon cable from the indicated right control knob. Remove the small circuit board (highlighted in yellow) from the main circuit board.
11. LCD is connected to the main circuit board by two ribbon cables. These are very fragile and must be carefully removed to ensure they do not break.
12. Cut two small rectangular pieces of plastic from an old credit card or similar information card and place them under a ribbon cable as they enter the connector.
13. Gently press the ribbon cable with a clean finger down against the plastic underneath, then pull the ribbon cable out of the connector.
The LCD is mounted in a metal frame that is attached to the main circuit board through a connector that is soldered at the indicated position. Remove the labels using a soldering iron and solder remover. Then use pliers to tighten the latch and remove the LCD component from the circuit board.
14. Remove the old LCD from the metal frame. To get the replacement LCD, type OPTREX 3231867 for the CD73 host. These are available on the Internet, such as pixelfix.
15. Carefully peel off the plastic film and apply it to both sides of the LCD. Then mount the LCD in a metal frame and replace the plastic liner.
16. Reassemble the radio in reverse order. Be careful when reconnecting ribbon cables because they are so fine.
Before reinstalling the radiator, remember to apply a thin layer of heat-conducting paste to the chip.
17. Finally, reinstall the BMW car stereo and check that it works properly. There is a test mode on CD73 unit. Turn on the radio and press the "m" button for about ten seconds. Use the + and - navigation test modes until it displays multiple test modes. Turn off the radio to exit test mode.