General information for display repairs
18.12.2023Preparation: Please pay attention to a clean environment and discharge yourself before touching the electronic components, for example by touching a radiator.
Contact types: There are three different contact variants:
The correct orientation of the display is essential for the function of the display. Most displays have a small nose on the edge. This must be placed in the notch of the recess for the display. Carefully clean the conductive rubbers and the contact surfaces of the displays. A speck of dust is sufficient to disturb the contact between the conductive rubber and the display and then leads to an incomplete display of the symbols. The same applies to the contact surface between conductor foil and conductive rubber. If some symbols are not displayed completely later, the contact between glass and conductive rubber or conductor foil is very often the cause.
Speedometer needles: Depending on the vehicle and instrument, the speedometer needles may need to be removed to access the display. To do this, use the needle puller by grasping under the speedometer needle and prying it out slowly and carefully. Particular care should be taken to pry the needle out straight and in axial direction. When bent, the plastic could break quickly. Heating the needle to around 50 ° C facilitates peeling. Mark exactly the position of the speedometer needles: These must be used again later.
Connectors (2.): Displays whose conductor foils are not ironed but plugged can be mounted quickly. On the board are connectors in which the conductor foil is inserted. You can only remove the conductor foil from the connector by pushing the very small clamping bar (as shown in the picture) upwards until the conductor foil can be removed. Make sure that you bend the conductor foil as less as possible.
Ironing welding (3.): When ironing a soldering iron with T-soldering tip and the associated silicone lip is needed. The silicone lip is pressed into the T-soldering tip. Then the T-soldering tip is mounted in the standard soldering iron instead of the original tip. There are the T-soldering tips with three different pin diameters of 4, 5 and 6mm depending on the existing soldering iron. Now, with a sufficiently large and heated silicone surface, the sensitive conductor foil can be ironed onto the board. High attention must be paid to a precisely positioned film, so that the right contacts are also perfectly aligned. At about 70-90 °C and a few seconds residence time of the T-soldering tip, the conductor foil should adhere to the board. Act carefully. In the worst case, you
- All notes serve only as an example and do not replace the workshop instructions of the automobile manufacturers! All information is supplied without guarantee!