Topics

Dead Or Just Sick?


secondchancesailor
 

Yesterday afternoon I was in the shack with the uBitx and everything was working fine.  I shut it down as always, and when I came back today and turned it on, it didn't work.  There is nothing but zeros in VFO A, VFO B shows 14 Mhz,  and the display does not respond to any input.   There is also no audio output at all.   It's hard to believe that all was well last time I used it, and 24 hours later it appears to be dead.    Any suggestions on where to start looking?    

Thanks,
Jim


barry halterman
 

I would reload the sketch and go from there. I had a similar issue.
Barry

On Wed, Mar 3, 2021, 5:36 PM secondchancesailor <jagillaspie@...> wrote:
Yesterday afternoon I was in the shack with the uBitx and everything was working fine.  I shut it down as always, and when I came back today and turned it on, it didn't work.  There is nothing but zeros in VFO A, VFO B shows 14 Mhz,  and the display does not respond to any input.   There is also no audio output at all.   It's hard to believe that all was well last time I used it, and 24 hours later it appears to be dead.    Any suggestions on where to start looking?    

Thanks,
Jim


Arv Evans
 

Jim

My suspicion would be a power supply problem.  Some power regulators
regulate upward, but a few regulate downward.  Those that regulate downward
cat let the voltage initially climb to excessive values before they bring the voltage
down to set value.  This is mostly confined to boost or buck regulation but
I guess it could happen in any where the regulation loop is slower than the voltage
rise when they first turn on.

Can you try the uBITX on a different power supply to see if the damage is slight
or massive.

Another possible problem would be that there has been a higher powered
transceiver operated close (on the same ground connection) to the uBITX?
High levels of HF signal could damage parts of the front-end.

Others will probably have more ideas to explore.

Arv
_._


On Wed, Mar 3, 2021 at 3:35 PM secondchancesailor <jagillaspie@...> wrote:
Yesterday afternoon I was in the shack with the uBitx and everything was working fine.  I shut it down as always, and when I came back today and turned it on, it didn't work.  There is nothing but zeros in VFO A, VFO B shows 14 Mhz,  and the display does not respond to any input.   There is also no audio output at all.   It's hard to believe that all was well last time I used it, and 24 hours later it appears to be dead.    Any suggestions on where to start looking?    

Thanks,
Jim


Malcolm
 

Hi Jim,
This sometimes happens to my uBITX V4 radio when it is connected to my laptop USB port.
I can restore the radio using either of two methods.

First method :
Switch OFF radio, disconnect USB cable, switch ON radio. Normal operation restored.

Or,

Second method :
Tap lower left corner of display.
Tap CW SETUP.
Tap Save & Reboot.
Tap Home.
Normal operation restored.

Hope this is useful, apologies for poor quality of photos.

73,
Malcolm
EI8FH


secondchancesailor
 

Hi Malcolm, 
Thanks for the suggestions and pictures.   I had already tried your first method with no luck.   I will give your second method a try when I get back to the shack.  The display was not responding to any input I tried, but I did not try the lower left corner as you suggest.   Hopefully that will do it.

73, Jim (w8ykg)


secondchancesailor
 

Hi Arv, thanks for the suggestions.   The power supply is an old Kenwood PS-30, and I switched it out with a 12V battery with no change.   I do have an Icom 718 downstairs that I transmitted with 2 or 3 times, but the power was set to 20 watts, so hopefully that was not the cause of the problem.   Also the uBitx was off at that time, although that might not make any difference.     

Jim 


secondchancesailor
 

Barry, that definitely sounds worth a try.  It is comforting to know that others have had a similar issue - it gives me hope that the uBitx might not be done for.  Thanks for the suggestion!

Jim


secondchancesailor
 

Unfortunately none of the suggestions were able to bring the uBitx V6 back to life.   I was able to get into the CW Setup / Save and Reboot as suggested by Malcolm, but it didn't solve the problem.  I have also switched out the power supply, and gone through the radio and made sure all pins and cables were seated.   I was not able to try reloading the software, and this might be a big hint - the computer no longer sees CH340.   I swapped out usb cables to make sure the cable was not the problem, and also rebooted the computer, but to no avail.    Any suggestions are welcomed!

Jim (w8ykg) 


Kelly Mabry
 

As a quirky thought reinstall the ch340 driver, but first check device manager for ch340 if it is there, delete and reinstall, especially if you see a '!' Next to it.

Kelly KD5AJ 


secondchancesailor
 

I forgot to mention I tried un-installing and re-installing the driver but it still didn't show up in Device Manager.   


Dj Merrill
 

Do you have a different computer that you can plug it into as a test?

-Dj


secondchancesailor
 

Yes, I tried it on a different computer with the same results.  


Arv Evans
 

Jim

Make a plan for attacking the problem so you can check off each step
as you do it.

1)  use the schematic to trace power to each section that needs power.

2) use the schematic to trace ground to each section that shows a ground.

3) use the schematic to trace signals through each section of the rig,
  • in Receive mode.
  • in Transmit mode.
This assumes you are adept at reading a schematic and at associating
the schematic with physical parts on the PCB.  While doing all this tracing
it might  be helpful to list the sections tested and if they are working.

If I remember correctly, I think you said your only test equipment was a
DVM.  That is probably adequate.  If you need to check for RF signals
you can build an RF Detector probe for the DVM.


If you run into something that is questionable you should feel free to
ask about it here on this forum.  Most of the members will be willing
to help.

Arv
_._


On Thu, Mar 4, 2021 at 11:16 AM secondchancesailor <jagillaspie@...> wrote:
Unfortunately none of the suggestions were able to bring the uBitx V6 back to life.   I was able to get into the CW Setup / Save and Reboot as suggested by Malcolm, but it didn't solve the problem.  I have also switched out the power supply, and gone through the radio and made sure all pins and cables were seated.   I was not able to try reloading the software, and this might be a big hint - the computer no longer sees CH340.   I swapped out usb cables to make sure the cable was not the problem, and also rebooted the computer, but to no avail.    Any suggestions are welcomed!

Jim (w8ykg) 


Arv Evans
 

Jim

Do not give up. 

image.png

If it can be built by hams, it can be rebuilt by hams.  Anything
can be repaired.  Bad components can be isolated and replaced. 
Blown PCB traces can be bridged with wire.  Software can
be replaced.  Microcontroller boards can be replaced and
reloaded with new software. 

Never, never, give up.

Arv
_._


On Thu, Mar 4, 2021 at 7:36 AM secondchancesailor <jagillaspie@...> wrote:
Hi Arv, thanks for the suggestions.   The power supply is an old Kenwood PS-30, and I switched it out with a 12V battery with no change.   I do have an Icom 718 downstairs that I transmitted with 2 or 3 times, but the power was set to 20 watts, so hopefully that was not the cause of the problem.   Also the uBitx was off at that time, although that might not make any difference.     

Jim 


Evan Hand
 

SecondChanceSailor,

Going on the picture, it looks like the Nano has stopped communicating with the Nextion.   

Based on the follow-up messages, the Nano is the most likely culprit, especially if it will not respond to the USB connection.

I would pull the Raduino board from the µBITX and try connecting to the PC.  The PC USB port should be able to power the Raduino and the Nano.  You can leave the Nextion connected for this, as the combined power draw is less than the standard USB port can supply (about 150 to 200 ma draw depending on the size of the display).  If the Nano can connect, then there is an issue with the mainboard and or wiring.

The next step is to pull the Nano from the Raduino/µBITX and see if you can get the PC to recognize the Nano.  If the Nano does connect, then there is a short or failure on the Raduino board.  You will need to hunt that down and repair it. 

If the Nano still cannot connect to the PC when not connected to the Raduino, then the Nano is most likely the issue.

Nanos are relatively inexpensive.  Just be sure to order the Nano with the headers separate, as they go on the side opposite of normal use.

I bought these recently, not the cheapest, but worked for me.:
https://smile.amazon.com/gp/product/B0713XK923/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Let us know the results of the above.

Good luck and happy hunting!
73
Evan
AC9TU


secondchancesailor
 

Great suggestions, Evan!   I'll give these a try when I get back into the shack.  That will probably be Monday before I can get to it.   I'll be sure to post my results here.  Thanks also for the link to the Nano you got for yours.

73
Jim w8ykg


secondchancesailor
 

Good advice, Arv!   My skills are limited, but I'm not about to give up.   I have too much time and too much $$ tied up in this so far.    I can "sort of" read a schematic, but I'm not great at it.   Will work through what I can, and I appreciate all the advice - this is a great group!

73
Jim w8ykg


secondchancesailor
 

Before I had to give it up for the weekend, I was able to pull the Raduino board and try connecting it to the pc.  It still did not connect.   Then I pulled the Nano and connected just it by itself to the pc.   The Nano board connected just fine.  So I loaded my last saved file with uBitx Manager.   Then I put the Nano back on the Raduino board, and it again failed to connect to the pc, and the radio still did not work.   At least I can rule out the Nano at this point. 


Evan Hand
 

secondchancesailor,

There is not too much on the Raduino board.  The regulator would seem to be working as the Nextion powers up.  That leaves some resistors, capacitors, and the Si5351a chip.  The Si5351a is hard to get right now.  Some are actually buying full clock breakout boards like this:
https://www.adafruit.com/product/2045?gclid=CjwKCAiAp4KCBhB6EiwAxRxbpEWmvvJ7FBscdJJOyLFO_-op4IWpmb6fOz5-Vf6Khy5UoEgf954ZHxoCfJAQAvD_BwE

And then either taking off the chip and moving it to the Raduionn or adapting the board to the Raduino.

Before going that route, check what happens on the 3.3v pin of the Nano:
Arduino Nano pinout
The above is from the normally top side.  When installed in the Raduino the board will be upside down, so take that into consideration when identifying the pins.  Some of the boards have the pins silked screened which makes it easier.  The alternative is to measure on the Raduino board.  What has happened to others is the Si5351a fails and then shorts the 3.3volt rail.  This has been traced back to cracked capacitors so also do a visual inspection of the board.

Here is the Raduino_tft board schematic:


https://www.hfsignals.com/wp-content/uploads/2019/12/raduino_tft.pdf

Check that C1 and C2 are not damaged.  Verify that you do get 3.3v on the 3v3 pin in the above drawings.  Also, verify that you get 3.3v on the 3v3 pin when the Nano is connected to the PC without the Raduino.

I will assume that you have not done SMD work before.  So you will need to decide if you want to learn, or contact HFSignals and ask to purchase a new Raduino board.  One other option is to purchase a clone Raduino board.  I have not done that for the v6, I was happy with the one I purchased for my v4.  I do not have a source for a clone, so HFSignals may be the only choice.

Again, let us know what you find/do.
73
Evan
AC9TT




secondchancesailor
 

Evan, thanks for the great information!   It will be Monday before I can get back to it, but you've given me a place to start looking.   I have done very little surface mount work, and am not a fan.   However I have a fairly decent soldering iron and a magnifying hood, so I can muddle my way through.   I'll report my findings when I have some.

Thanks Again!
Jim