No display on LED, and buttons do not work
No display on LED, and buttons do not work
Trouble shooting chart
Yes 
Check whether there is correct contact between XS301 and XP82
Yes 
Check VCC(M5V) voltage on the power and front board
Yes 
No
No
Correct connection
Fix power supply board top a power supply for should electric circuit
Check there are STB, SDA | No |
and SCK signals on XS301 |
|
on the front board. |
|
Check the U1’s pin 34,35,39 arrive the XP82 connect condition
XP82 (PIN 4 CLK) | XP82 (PIN6 DOUT) |
Yes
1.Check whether bad solder exists on
U301 and pins of LED,
2.Check whether the circuit connected toNo K302, K303 and K301 is broken,
3.Check whether R1, R3 on front board and R81,R82 and R83 on MEPG board are
Correct connection
Yes 
Replace U301 or LED
