All communications to Hans regarding specific orders/problems need to be done via the support system at qrp-labs.com, if I understand correctly.
No, the QMX definitely should not have failed after a short time of just listening - the exception being if the voltage on your power supply was way too high, e.g. 14V instead of 12V.? (Some fully charged so-called 12V batteries are really 14.4V or 13.8V - these should not be used with QMX without a voltage reducing circuit of some sort.)
But there are also possible 'infant mortality' parts failures that just happen - such failures are reasonably rare, but they do happen.
Please see the reply I made to your other post for some measurements to take.
Stan KC7XE
