According to many years' maintenance experience, engineers of Keyu Circuit Board Maintenance Technology Training Center judged that it was caused by the failure of the D8 chip of LCECPU40 circuit board. Because the manufacturer of KONE 3000 elevator wrote a program in D8 chip of LCECPU40 circuit board to lock the elevator 10000 times, that is to say, every time the elevator starts to run, the counter in D8 chip counts once, and when it reaches 10000 times, it outputs the information that it is forbidden to enter the debugging menu. In this way, people who are not from KONE elevator manufacturers can't find elevator information through the buttons in the LCECPU40 circuit board. If there is a special decoder of KONE elevator manufacturer, the decoder can solve the elevator locking failure of 10000 times; if there is no decoder, the replacement of D8 chip can solve the elevator locking failure of 10000 times. The method is as follows:

Turn the maintenance switch 270 in the Kone elevator controller to the maintenance mode and turn off the main power supply of the elevator. Pull out the D8 chip on the LCECPU40 circuit board and replace it with a new NARAM chip. Turn on the power of the elevator, use the operation button on LCEEPU to enter the menu 1-99, and set the parameter to 2. At this point, the system parameters will be restored to the default values of EPROM (when doing so, the elevator must stop at the ground floor, and 77U and 6 1U must be valid). Use the operation button on LCECPU to enter menu 5-7 and set the parameter to 1. At this time, the elevator will download the LON protocol (the elevator must stop at the basement level, and 6 1U is valid). After the above steps are completed, the elevator must learn by itself. The self-learning method is to stop the elevator at the bottom floor (6 1U is effective), enter menu 5-2 through the operation button on LCECPU, set the parameter to 1, and then turn the 270 switch to the normal position. When the LCECPU electronic board emits two beeps, the elevator will start slow self-learning in the hoistway until the top floor exceeds the top floor horizontal position, and then return to the top floor horizontal position. At this point, the LCECPU digital tube will flash for about two seconds and beep, indicating the completion of self-learning. LCECPU digital tube will display the elevator floor at this time (this floor is the number of elevator floors in the system, which may be different from the actual number of floors. The reason is that when the height of a single floor exceeds 5 meters, it is necessary to set a fake floor, which will play the role of setting the floor sign of menu 3. Before setting these parameters, you need to know that there is a fake floor between two floors. After the self-learning is completed, turn the 270 switch to the maintenance position to start parameter setting. The parameters that must be set include menu 1 elevator parameters and 3-floor signs. The specific settings will depend on the actual situation on site. After the parameter setting is completed, the system must be powered off, and then powered on after all the indicator lights are turned off, otherwise the changed parameters will not work.

By adopting the above method, the failure that KONE 3000 elevator can't enter the debugging menu can be repaired without the special decoder of KONE elevator manufacturer.