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Finished my QMX for 12v.? Had to use the wire jumper to put in firmware update mode.? Was able to download ver. 017.? Running about 10 v. when I turn on, iit starts, shows the version no.? Then a 3.5 mhz frequency shows.? It immediately shows "Shut Down!" and I have to shut down the power supply to make it turn off.? While it is running it is show about 80 to 90 ma.? My power supply is adjustable for both voltage and amps. I soldered all connections again but no luck.? Where should I start to look?? Thanks for the help;? Not my first QRP-Labs kit.

73,
Gary K4VIG

On Wed, Apr 10, 2024 at 05:57 PM, Gary K4VIG wrote:

about 80 to 90 ma

Hello Gary,

this is fine. I guess, there is a short (not a dangrous) around the connection between the main board and the controls board or on the controls board.
To switch on the QMX regular you have to connect to the power supply and press the left encoder. Pressing again "longer" starts the shut down procedure.
I guess after connecting your QMX to the power it switches on direct and after this shows "Shut down!" for eternity.

Lets have a look on the schematic_rev2.pdf page 3. JP302 is the connector to the main board. S304 (on the left) is the push button of the left encoder. Pressing this encoder connects pin 5 to GND. In your QMX pin 5 (JP302) seems to be connected to GND all the time. Maybe there is a bridge at the connector or direct at the encoder.

To identify the pins at the controls board have a look in this discussion. There is a drawing of the pin header. So you could identify the pins in in the hardware (ref GND).

73, Ludwig

Thanks Ludwig for your input.? Finally got back to the project.? I took a look at the schematic and then checked where JP302 connects to S304. Also using the diagram on page 11 in assembly manual On JP304 the following is found.?
Pin 1 Ungrounded? ? ? Pin 2 Ungrounded
Pin 3 Grounded? ? ? ? ? Pin 4 Ungrounded
Pin 5 Ungrounded? ? ? Pin 6 Ungrounded
Pin 7 Grounded? ? ? ? ? Pin 8 Ungrounded

Pin 5 on JP302 and top left pad on S304 are connected.
Top right pad on S304 is grounded.
Pin 8 on JP302 and bottom left on S304 are connected.
Pin 4 on JP302 and bottom right of S304 are connected

Pin 6 on JP302 and top left? pad on S301 are connected.
Top right pad on S301 is grounded.
Pin 1 on JP302 and bottom left pad on S301 are connected.
Pin 3 on JP302 and bottom right pad on S301 are connected.

Does this look okay?? However, if I start the QMX by pushing S304 , the display lights, shows version and then a 3.5 mhz. frequency.? It then indicates "Shut Down!"? If I remove the Plug-in Controls board, the display continues to show "Shut Down" and I must turn it off with the power supply.

Gary K4VIG

Initially I installed the connector pins on the control board the wrong way.? When assembling the control board onto the main board it was not obvious that the pins ere not contacting.? Fortunately my low band QMX was correct so when I used its control board in the newly built hi band QMX all was well.? So I found on line suitable replacement connector pins.
Note that the QMX can be started without the control board fully connected.? So maybe you put the pins in with the slightly shorter length and may be getting some connection.? I would check between the boards if they are connecting.

Thanks Chris for the reply.? I did plug the control board in to the main board and check for connections on all eight pins of S302,? I wondered if maybe the male pins were not touching all the layers in the main board.? That will take come doing to check that.? Can you share where you found the suitable connector pins?

Gary K4VIG

Gary, the pins on the 2 encoders are easily, without knowing, shorted to ground while installing them.? With a DMM check continuity between the metal encoder casing and each of the encoder's pins. There should be no continuity from any pin to the case of the encoder. If there is, then you've likely found the issue.
--
73
de Roy - KI0ER
Littleton, Colorado USA

Gary,
simple check: plug in the Controls board in the mainboard, connect Vin to the QMX and check voltage at pin 5 of JP302.

QMX off: around Vin
left encoder pressed: 0 V ;GND
left encoder not pressed and QMX on: around Vin
left encoder pressed again and QMX on: 0 V; GND

If you see this the controls board until the header works right. So there maybe a problem around the connection to the main board or on the mainboard

73 Ludwig

On Thu, Apr 11, 2024 at 06:56 PM, Gary K4VIG wrote:

If I remove the Plug-in Controls board, the display continues to show "Shut Down" and I must turn it off with the power supply

This would maen no short? between GND and pin 5 on the controlsboard.
Pressing the left encoder should switchoff Q202 on the mainboard and this gives the signal "pressed" to the controller. If Q202 would be off all the time the controller would start shutdown immediately. But why not really to an end is the next question. At first it would be fine to check voltages (see my post before).

73 Ludwig

73 Ludwig

Looking on all information the best explanation would be a short between pin 5 and GND on the mainboard (connector JP201).

For replacement pins I bought a kit of connectors from Amazon, needed some work to use!? I do have a vacuum de-soldering station that helped remove the old connector.?

Forgot to paste the link to the connector kit.
www.amazon.com/gp/product/B07CWSXY7P/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Roy, thanks for the suggestion.? I checked both of them and there are no shorts.

Gary

Ludwig, there is no short between pin 5 and GND on the mainboard (connector JP201.

I checked voltages on pin 5 on JP302 on Control Board.

Vin 10 v.??
With QMX off:? 10 v
With left encoder pressed: 10 v.
With left encoder not pressed: 10 v.
With left encoder pressed again: 10:v

Also check on mainboard pin 5 with same results.

Gary

On Fri, Apr 12, 2024 at 03:51 PM, Gary K4VIG wrote:

With left encoder pressed: 10 v.

Hello Gary,

IMHO there's a fault. Watch schematic.
page 1 left upper corner: V_IN via 100 k to PWR_ON
page 2: PWR_ON is connected to JP201 pin 5 (connector to JP302 on Controls board)
page 3: JP302 pin 5 is connected to S304 (button of left encoder)
other contact of button of left encoder is connected to GND.
When pressing left encoder JP302 pin 5 should be connected to GND = 0 V.

73 Ludwig