Chris, G5CTH,?documented a process to check out each of the buck converter boards in this post:
It requires a controllable voltage, current limiting,
?power supply.? You could do some of the tests with just a voltage-controllable supply.
Hans has posted a description of the startup process that the QMX goes through.??
/g/QRPLabs/message/103064Use this with the schematic and board layout to work through where the voltage is getting lost.? Be very careful when probing.? When the board is removed from the case, it is easy to push things in the wrong direction and wipe out the main board (don't ask).
73
Evan
AC9TU
