Problem of powering up!

mangOH Green
1

Hi guys,

I’ve got a mangOH WP series dev kit with wp8548 in my hand. I got a problem powering this little thing up. When I connected the board and my PC with USB cable. the typical story is that only the PWR LED turned on, and my PC cannot even know there is new hardware connected, so the device also cannot be PINGed . There were several times that I could connect successfully and everything worked fine. Is there way I could diagnose or fix?

Thanks.
Ji

2

I have checked the different Power supply voltages, and they all look fine.

3

If you have access to a serial port, I would suggest connecting the DB-9 connector and observing the output on startup. That might give some clues as to what the problem is.

4

what firmware version are you using? Can you do a cm info ?

5

Thanks guys! I just found it is because the POWER_ON switch, the first switch of SW401, was not all the way flipped to ON. The intermittent connection of power caused the abnormal thing.