Blue LED - Working Good (Back Panel) Red LED - Working Good (Front Panel)
Troubleshooting Steps
Check if the ETH LED is blinking. If ETH green and yellow light are on and the blue LED is off, please flash a new sd card first. If the blue light is still off,that would be a hardware defect issue.
If the green and yellow LED is off, try to make sure the power adapter is good. You may check by replacing it with a 5V-3A phone charger with the type-C cable to see if the problem is resolved.
If the hotspot connects internet via Wi-Fi, please check if the red light is on through the front panel, if not, that would be a hardware defect issue.