**Replace the main board 
(located at the bottom of the front end of the machine, replace the chassis)**

**operating steps**

Turn off the machine (graph 317)
{{ :starry:317.png?nolink&600 |}}
                                                          graph 317
Open the bottom cover of the main board (graph 318)
{{ :starry:318.png?nolink&600 |}}
                                                          graph 318
Remove 4 fixing screws of the main board (Fig. 319,320,321,322)
{{ :starry:319.png?nolink&600 |}}
                                                          graph 319
{{ :starry:320.png?nolink&600 |}}
                                                          graph 320
{{ :starry:321.png?nolink&600 |}}
                                                          graph 321
{{ :starry:322.png?nolink&600 |}}
                                                          graph 322
Disconnect all line interfaces on the main board (you can take photos and record the corresponding interfaces of the line in advance to avoid replacing the wrong connection line) (graph 323)
{{ :starry:323.png?nolink&600 |}}
                                                          graph 323
Disconnect the wifi wire interface (graph 324)
{{ :starry:324.png?nolink&600 |}}
                                                          graph 324
Remove the chassis floor with 12 screws (Fig. 325,326,327,328)
{{ :starry:325.png?nolink&600 |}}
                                                          graph 325
{{ :starry:326.png?nolink&600 |}}
                                                          graph 326
{{ :starry:327.png?nolink&600 |}}
                                                          graph 327
{{ :starry:328.png?nolink&600 |}}
                                                          graph 328
{{ :starry:329.png?nolink&600 |}}
                                                          graph 329
Disconnect wire wire interface (graph 330)
{{ :starry:330.png?nolink&600 |}}
                                                          graph 330
Cut the tie band (graph 331)
{{ :starry:331.png?nolink&600 |}}
                                                          graph 331
With a new mainboard (graph 332)
{{ :starry:332.png?nolink&600 |}}
                                                          graph 332
Install 4 fixing screws on the main board (Fig. 333,334,335,336)
{{ :starry:333.png?nolink&600 |}}
                                                          graph 333
{{ :starry:334.png?nolink&600 |}}
                                                          graph 334
{{ :starry:335.png?nolink&600 |}}
                                                          graph 335
{{ :starry:336.png?nolink&600 |}}
                                                          graph 336
Link all line interfaces, please refer to the detailed motherboard diagram (graph 337, graph 338)
{{ :starry:337.png?nolink&600 |}}
                                                          graph 337
{{ :starry:338.png?nolink&600 |}}
                                                          graph 338
Install 12 screws on bottom cover of chassis (graph 339)
{{ :starry:339.png?nolink&600 |}}
                                                          graph 339
Install the motherboard bottom cover (graph 340)
{{ :starry:340.png?nolink&600 |}}
                                                          graph 340