With the display board out of the radio, I measured 0 ohms between pin 2
of the 4 pin connector (GND), and the pad to the right side of C301,
which is marked VCC on the trace diagram. Seems "odd." Possible shorted
C301? Unfortunately, I have no surface mount skills or equipment.
What is a path forward?
73,
-Al WA1TYB
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On 3/22/2024 15:44, Greg McCain via groups.io wrote:
Hopefully something simple and/or obvious.
Don't forget to check the 2 header connectors on the main board too.
Good hunting. Let us know if you solve it.
Greg KI4NVX
Yahoo Mail: Search, Organize, Conquer
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On Fri, Mar 22, 2024 at 5:05 PM, Al Simons
<al@...> wrote:
Greg, THANK YOU.? Pulling the display board lets it come up, drawing
~150mA at 6V. The terminal program is running, so it seems that at
least
part of the CPU is OK.? Now to figure out what I did wrong with the
display board!
Again, thanks.
-Al WA1TYB
On 3/22/2024 14:36, Greg McCain via groups.io wrote:
> Just a quick thought.
>
> Without the control board will the unit even power up since the
rotary
> push to power on won't be available?
>
> You might try just removing the display.
> If the current stays up, then the fault might be in the display
board
> or the 5v power board.
>
> I've seen other posts where faults/ bridges/shorts in the power
> boards' connector chains have caused odd problems. I took the advice
> in the build instructions and clipped the one set of pins back
about a
> millimeter or so because I could definitely see I that a few
were too
> long and extended past the solder pads and awful close to other
items.
>
>
> Greg
>
>
> Yahoo Mail: Search, Organize, Conquer
>
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>
>? ? On Fri, Mar 22, 2024 at 2:32 PM, Al Simons
>? ? <al@...> wrote:
>? ? Just completed my Rev 3 QMX assembly. It performs the USB stick
>? ? emulation ok, to place the FW file on board. I did this both on
>? ? initial power-up and by jumpering AUX2 to GND. However, after FW
>? ? load, when I press the left knob it draws power for an
instant and
>? ? then powers back down to 0.000A.? I'm using 7V, limited to 200mA.
>? ? I have inspected all my joints w/ a magnifier, all seem fine but
>? ? I'm considering buying a USB microscope.
>
>? ? To start troubleshooting I want to check the power boards.? For
>? ? easier access, is it safe to power up the unit without the
control
>? ? board and display boards plugged in?
>
>? ? I've been monitoring this group since I placed my order.? I think
>? ? I remember a reference to a troubleshooting guide by Hans, and
>? ? another report of this failure mode, but I can't find either.
>? ? Pointers to either would be greatly appreciated. I'm aware of the
>? ? troubleshooting log Hans has posted about units he's fixed,
but it
>? ? doesn't mention this failure.
>
>? ? Thanks for any advice and pointers.
>? ? 73,
>? ? -Al WA1TYB
>
>
