Problem with Bob3

[Jermncoco]

I have successfully assembled the kit, performed the power tests with JP2 closed. As soon as I open JP2, unit will not power on with ADJ switch. Have 5V at in pin on Bob3, between reference point and Gnd pin. 0V at other 3 pins and no change when switch pressed. D1 doesn't light up either.

[Jermncoco]

Update:
Have 4V at VBAT with USB charging battery
4V at SW,
0V at on/off,
0V at out on Bob3

[jye1]

Please first disconnect the ON/OFF pin and press ADJ to see if the scope can be turned on or not.

[Jermncoco]

No, there is no change with on/off disconnected. The Oscilloscope comes on and functions with JP2 closed

[jye1]

Did you check the conductivity between BOB3 pin 5 and GND? When ADJ is pushed down this should have resistance close to zero.

[Jermncoco]

It reads 3.67 volts between SW and Gnd. When ADJ is pressed it drops to zero

[Jermncoco]

The resistance between Grd and pad 5 is 1.1 Mohm and yes drops to zero when ADJ is pressed

[jye1]

Can you please take a close look at the SMD soldering of BOB3? It may be defective. You can contact us at jyetek@gmail.com to request a replacement if this problem can not be fixed.

[Jermncoco]

I pulled Bob3 loose and tested all of the components. It seems that the SI2301 MOSFET is bad. I will change it out and update

[jye1]

Ok, please contact us if it still doesn't work.