There appears to be a short of some sort dragging down your 5V supply.? This will prevent the display from turning on, and prevent the receiver and transmitter from working properly.
?
If you can put a current limit on your supply, it would be safer while you debug, about 250-300mA at 7V.
?
A short can be because of soldering, or purely mechanical, or can be from a device failure.? When the front panel is installed on the QMX, there is very little clearance between several items - look carefully, and see if anything is touching that shouldn't.? Typical places are by the power-in connector, the bodies of the encoders, the cut-off pins that connect the display to its carrier board, and that display mounting tab that needs bent over.?
?
If you don't see anything mechanical, I would next remove the 5V smps, then (with power off, obviously) measure the resistance between the 5V VCC pin and ground on the motherboard, and do the same on the smps board.?? If there is no fault, these should be a few k-ohms each.? If either is a much lower number of ohms, that board is where you start looking for the short or problem.
?
Stan KC7XE
