Defective STEMLab 125-14 Ordered from Mouser
Posted: Tue Mar 16, 2021 2:00 am
Last week, I ordered a STEMLab 125-14 Starter Kit from mouser.com. After opening the box and connecting the included 5V microUSB power supply to the PWR connector, nothing happened. No LED lights came on.
I inspected the PCB very closely on both sides, but I don't see any damage or missing components. There is no obvious reason for the problem.
Next, I looked at the schematic and started probing the DC-DC converter circuitry at the LTC3615 ICs. All of the voltages seem to be OK, except +3.3 V. Instead, +3.3 V measures -0.4 V. Also, the PGOOD output from the LTC3615 is low (pulled to ground). As a result, the board will not boot up.
Thus, I received a unit with a broken +3.3V output. I contacted Mouser, and they told me to contact Redpitaya for help. I need a replacement unit for work, so I cannot wait a long time to go through the RMA process.
Please help.
I inspected the PCB very closely on both sides, but I don't see any damage or missing components. There is no obvious reason for the problem.
Next, I looked at the schematic and started probing the DC-DC converter circuitry at the LTC3615 ICs. All of the voltages seem to be OK, except +3.3 V. Instead, +3.3 V measures -0.4 V. Also, the PGOOD output from the LTC3615 is low (pulled to ground). As a result, the board will not boot up.
Thus, I received a unit with a broken +3.3V output. I contacted Mouser, and they told me to contact Redpitaya for help. I need a replacement unit for work, so I cannot wait a long time to go through the RMA process.
Please help.