Topics

LCD problems #v3


Kit Peters
 

I have a uBITX v3 that I've been messing with for a little while. I had it all together and working (at least as far as the LCD turning on and the tuning knob working - I didn't test TX / RX) last week. I don't know what happened - maybe I forgot to turn it off - but the LCD wouldn't come up yesterday, even though I confirmed that there were 12 volts coming to the Arduino socket on the main board. I turned it off for a bit, and the LCD came back up, but the volume pot started to smoke. So I turned it off, and turned it back on, and the LCD came on, but it was just a bunch of blocks across the first line.  Also, there is a tabbed component - maybe a voltage regulator - off the side of the Arduino and the tab was super hot to the touch. Any thoughts?

--
Kit Peters, W0KEH
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Evan Hand
 

Kit,
My first guess is that you have the audio and digital cables reversed.  Check carefully that the tuning encoder goes to the Raduino (board with the display) and not the mainboard.  That would be one of the reasons for the volume control to smoke.  If this is the case, then you will need to verify a lot of the Raduino board, as you may have blown the Nano and the Si5351.  Remove the Raduino board with the display, disconnect the Digital controls cable, and see if it comes up when powered from a USB 5 volt supply (Can be a computer USB port).  If it will not power up, then I would pull the Nano and test the regulator supplying 12 volts to pin 15 or 16 of the connector that plugs into the mainboard.  You should get 5 volts out of the regulator.

The other tests that I can think of would depend on the test equipment that you have.  I will assume that you have a DMM or multimeter of some kind to check voltages.  Do you have an oscilloscope or frequency counter to measure the VFO clock signals from the Raduino board?  How comfortable are you with downloading new programs to the Nano?

Let us know if you did swap the audio and digital connectors by mistake (this happens more often then you would think.  I wish that HFSignals had made them different to prevent this problem. They are the only two connections that can be inserted in the wrong location and cause damage.

As a side note, the Raduino regulator does run hot, so not always an indication of a problem.  It also has thermal and overcurrent protection built-in to protect the regulator and downstream equipment.

Good luck with getting your rig back to operational.
73
Evan
AC9TU


Kit Peters
 

I'll check on the connectors. It certainly seems plausible that I might have done so - after I installed the front panel breakout board I found, I didn't relabel the connectors.

I have a DMM and a scope, and I think my MFJ antenna analyzer has a frequency counter on it. Where can I find test specs?

As for downloading new programs to the Nano, I've never done it before, but I'm comfortable giving it a go.


On Tue, Sep 22, 2020 at 10:25 AM Evan Hand <elhandjr@...> wrote:
Kit,
My first guess is that you have the audio and digital cables reversed.  Check carefully that the tuning encoder goes to the Raduino (board with the display) and not the mainboard.  That would be one of the reasons for the volume control to smoke.  If this is the case, then you will need to verify a lot of the Raduino board, as you may have blown the Nano and the Si5351.  Remove the Raduino board with the display, disconnect the Digital controls cable, and see if it comes up when powered from a USB 5 volt supply (Can be a computer USB port).  If it will not power up, then I would pull the Nano and test the regulator supplying 12 volts to pin 15 or 16 of the connector that plugs into the mainboard.  You should get 5 volts out of the regulator.

The other tests that I can think of would depend on the test equipment that you have.  I will assume that you have a DMM or multimeter of some kind to check voltages.  Do you have an oscilloscope or frequency counter to measure the VFO clock signals from the Raduino board?  How comfortable are you with downloading new programs to the Nano?

Let us know if you did swap the audio and digital connectors by mistake (this happens more often then you would think.  I wish that HFSignals had made them different to prevent this problem. They are the only two connections that can be inserted in the wrong location and cause damage.

As a side note, the Raduino regulator does run hot, so not always an indication of a problem.  It also has thermal and overcurrent protection built-in to protect the regulator and downstream equipment.

Good luck with getting your rig back to operational.
73
Evan
AC9TU



--
Kit Peters, W0KEH
GPG public key fingerpint: D4FF AA62 AFEA 83D6 CC98 ACE5 6FAE 7E74 7F56 ED1D
Hello to any and all NSA, DEA, or other government or non-government agents reading this email.  Tell me about your life; I'll tell you about mine.


Evan Hand
 

Start with the off-board test.  If the Raduino checks out, then measure the 3 clock signals on the Raduino per the attached schematic.  You can connect the digital I/O connector to the Raduino when not connected to the mainboard.  You should also review the circuit description on HFSignals site to figure out what the three clock signals should be.

In general and approximate:
Clock2 Pin 14 should be 45HMz + the frequency setting on the uBITX display
 
Clock1 Pin 11 should be either 33MHz or 57MHz depending on upper or lower sideband selection. (depending on how you intrepret the comment on this signal, you can say that it is backwords, or remember that the first mixer inverts the sideband.   For me, it is 57MHz when usb is selected.

Clock0 Pin 8 should be around 11.996MHz depending on BFO setting

I have measured these signals both in and out of the circuit with my 100MHz scope.  The TPs are 12, 15, and 18

Here is the circuit description for the v4.  It is the same as the v3.
https://www.hfsignals.com/index.php/ubitx-v4-archived/

Hope this helps
73
Evan
AC9TU


Kit Peters
 

Just wanted to give an update - when I connect the Raduino to a computer via a USB port (disconnected from the main board) the LCD powers up and the first line is full of blocks. So now I measure the clock signals as you described, correct?

On Tue, Sep 22, 2020 at 10:57 AM Evan Hand <elhandjr@...> wrote:
Start with the off-board test.  If the Raduino checks out, then measure the 3 clock signals on the Raduino per the attached schematic.  You can connect the digital I/O connector to the Raduino when not connected to the mainboard.  You should also review the circuit description on HFSignals site to figure out what the three clock signals should be.

In general and approximate:
Clock2 Pin 14 should be 45HMz + the frequency setting on the uBITX display
 
Clock1 Pin 11 should be either 33MHz or 57MHz depending on upper or lower sideband selection. (depending on how you intrepret the comment on this signal, you can say that it is backwords, or remember that the first mixer inverts the sideband.   For me, it is 57MHz when usb is selected.

Clock0 Pin 8 should be around 11.996MHz depending on BFO setting

I have measured these signals both in and out of the circuit with my 100MHz scope.  The TPs are 12, 15, and 18

Here is the circuit description for the v4.  It is the same as the v3.
https://www.hfsignals.com/index.php/ubitx-v4-archived/

Hope this helps
73
Evan
AC9TU



--
Kit Peters, W0KEH
GPG public key fingerpint: D4FF AA62 AFEA 83D6 CC98 ACE5 6FAE 7E74 7F56 ED1D
Hello to any and all NSA, DEA, or other government or non-government agents reading this email.  Tell me about your life; I'll tell you about mine.


Evan Hand
 

Kit
try adjusting the contrast control. If you can not get the display to show characters, then most likely the Nano is damaged.  Checking for the clock signals would not make sense if the Nano is bad.  The Nano programs the Si5351 DDS, so there may or may not be a clock frequency output. 


73
Evan
AC9TU


Kit Peters
 

Contrast control only makes darker / lighter blocks. Guess my Nano is hosed.


On Thu, Sep 24, 2020, 12:39 Evan Hand <elhandjr@...> wrote:

Kit
try adjusting the contrast control. If you can not get the display to show characters, then most likely the Nano is damaged.  Checking for the clock signals would not make sense if the Nano is bad.  The Nano programs the Si5351 DDS, so there may or may not be a clock frequency output. 


73
Evan
AC9TU


Evan Hand
 

Kit,
Based on what you have reported, then yes the Nano is most likely toast. Be sure to get one without the headers solder to the board. The Raduino has the header mounted on the underside of the Nano. 


73
Evan
AC9TU


Arv Evans
 

Kit

It may be the display that is defective, or maybe just mis-wired.
If the display is not being initialized it will show only the top row 
of blocks.  Not being initialized can result from short or open 
connections to the EN, RS, RW, or any of the Data leads.  
Best test is to try another LCD display to see if the problem 
persists.  Since you can vary the contrast it would seem that 
the present LCD is probably working, hence the suspicion 
that an LCD control lead is not working properly.  A DVM or 
oscilloscope on one of the LCD control pins should show 
data flow during the initial turn-on period.  You have to look 
closely though because the leads will be active for a very 
short period of time.  If data flow is indicated then the Arduino 
is probably still good.

Arv  K7HKL
_._


On Thu, Sep 24, 2020 at 12:28 PM Kit Peters <popefelix@...> wrote:
Contrast control only makes darker / lighter blocks. Guess my Nano is hosed.

On Thu, Sep 24, 2020, 12:39 Evan Hand <elhandjr@...> wrote:

Kit
try adjusting the contrast control. If you can not get the display to show characters, then most likely the Nano is damaged.  Checking for the clock signals would not make sense if the Nano is bad.  The Nano programs the Si5351 DDS, so there may or may not be a clock frequency output. 


73
Evan
AC9TU


Kit Peters
 

At a certain point it becomes more economical, I think, to replace the Nano, given that a clone only costs ten dollars or so. 😁

On Thu, Sep 24, 2020, 13:40 Arv Evans <arvid.evans@...> wrote:

Kit

It may be the display that is defective, or maybe just mis-wired.
If the display is not being initialized it will show only the top row 
of blocks.  Not being initialized can result from short or open 
connections to the EN, RS, RW, or any of the Data leads.  
Best test is to try another LCD display to see if the problem 
persists.  Since you can vary the contrast it would seem that 
the present LCD is probably working, hence the suspicion 
that an LCD control lead is not working properly.  A DVM or 
oscilloscope on one of the LCD control pins should show 
data flow during the initial turn-on period.  You have to look 
closely though because the leads will be active for a very 
short period of time.  If data flow is indicated then the Arduino 
is probably still good.

Arv  K7HKL
_._


On Thu, Sep 24, 2020 at 12:28 PM Kit Peters <popefelix@...> wrote:
Contrast control only makes darker / lighter blocks. Guess my Nano is hosed.

On Thu, Sep 24, 2020, 12:39 Evan Hand <elhandjr@...> wrote:

Kit
try adjusting the contrast control. If you can not get the display to show characters, then most likely the Nano is damaged.  Checking for the clock signals would not make sense if the Nano is bad.  The Nano programs the Si5351 DDS, so there may or may not be a clock frequency output. 


73
Evan
AC9TU


Arv Evans
 

Kit

But if the problem is wiring connectivity then replacing either the LCD
and/or the Nano will probably be unsuccessful.  Then you will still have to 
correct the original problem!    8-)

Arv
_._


On Thu, Sep 24, 2020 at 12:47 PM Kit Peters <popefelix@...> wrote:
At a certain point it becomes more economical, I think, to replace the Nano, given that a clone only costs ten dollars or so. 😁

On Thu, Sep 24, 2020, 13:40 Arv Evans <arvid.evans@...> wrote:
Kit

It may be the display that is defective, or maybe just mis-wired.
If the display is not being initialized it will show only the top row 
of blocks.  Not being initialized can result from short or open 
connections to the EN, RS, RW, or any of the Data leads.  
Best test is to try another LCD display to see if the problem 
persists.  Since you can vary the contrast it would seem that 
the present LCD is probably working, hence the suspicion 
that an LCD control lead is not working properly.  A DVM or 
oscilloscope on one of the LCD control pins should show 
data flow during the initial turn-on period.  You have to look 
closely though because the leads will be active for a very 
short period of time.  If data flow is indicated then the Arduino 
is probably still good.

Arv  K7HKL
_._


On Thu, Sep 24, 2020 at 12:28 PM Kit Peters <popefelix@...> wrote:
Contrast control only makes darker / lighter blocks. Guess my Nano is hosed.

On Thu, Sep 24, 2020, 12:39 Evan Hand <elhandjr@...> wrote:

Kit
try adjusting the contrast control. If you can not get the display to show characters, then most likely the Nano is damaged.  Checking for the clock signals would not make sense if the Nano is bad.  The Nano programs the Si5351 DDS, so there may or may not be a clock frequency output. 


73
Evan
AC9TU


Kit Peters
 

That's true, but given the circumstances that caused the problem (transposing the analog and digital connectors) isn't it more likely that the Nano itself is fried than a connectivity problem between the Nano and the LCD?

On Thu, Sep 24, 2020 at 2:53 PM Arv Evans <arvid.evans@...> wrote:
Kit

But if the problem is wiring connectivity then replacing either the LCD
and/or the Nano will probably be unsuccessful.  Then you will still have to 
correct the original problem!    8-)

Arv
_._


On Thu, Sep 24, 2020 at 12:47 PM Kit Peters <popefelix@...> wrote:
At a certain point it becomes more economical, I think, to replace the Nano, given that a clone only costs ten dollars or so. 😁

On Thu, Sep 24, 2020, 13:40 Arv Evans <arvid.evans@...> wrote:
Kit

It may be the display that is defective, or maybe just mis-wired.
If the display is not being initialized it will show only the top row 
of blocks.  Not being initialized can result from short or open 
connections to the EN, RS, RW, or any of the Data leads.  
Best test is to try another LCD display to see if the problem 
persists.  Since you can vary the contrast it would seem that 
the present LCD is probably working, hence the suspicion 
that an LCD control lead is not working properly.  A DVM or 
oscilloscope on one of the LCD control pins should show 
data flow during the initial turn-on period.  You have to look 
closely though because the leads will be active for a very 
short period of time.  If data flow is indicated then the Arduino 
is probably still good.

Arv  K7HKL
_._


On Thu, Sep 24, 2020 at 12:28 PM Kit Peters <popefelix@...> wrote:
Contrast control only makes darker / lighter blocks. Guess my Nano is hosed.

On Thu, Sep 24, 2020, 12:39 Evan Hand <elhandjr@...> wrote:

Kit
try adjusting the contrast control. If you can not get the display to show characters, then most likely the Nano is damaged.  Checking for the clock signals would not make sense if the Nano is bad.  The Nano programs the Si5351 DDS, so there may or may not be a clock frequency output. 


73
Evan
AC9TU



--
Kit Peters, W0KEH
GPG public key fingerpint: D4FF AA62 AFEA 83D6 CC98 ACE5 6FAE 7E74 7F56 ED1D
Hello to any and all NSA, DEA, or other government or non-government agents reading this email.  Tell me about your life; I'll tell you about mine.


Arv Evans
 

Kit

Depends on your financial situation.  Verifying connectivity could cost 
less, and might actually solve the problem while you are waiting on 
delivery of a new LCD and a new Nano.

Arv
_._


On Thu, Sep 24, 2020 at 2:16 PM Kit Peters <popefelix@...> wrote:
That's true, but given the circumstances that caused the problem (transposing the analog and digital connectors) isn't it more likely that the Nano itself is fried than a connectivity problem between the Nano and the LCD?

On Thu, Sep 24, 2020 at 2:53 PM Arv Evans <arvid.evans@...> wrote:
Kit

But if the problem is wiring connectivity then replacing either the LCD
and/or the Nano will probably be unsuccessful.  Then you will still have to 
correct the original problem!    8-)

Arv
_._


On Thu, Sep 24, 2020 at 12:47 PM Kit Peters <popefelix@...> wrote:
At a certain point it becomes more economical, I think, to replace the Nano, given that a clone only costs ten dollars or so. 😁

On Thu, Sep 24, 2020, 13:40 Arv Evans <arvid.evans@...> wrote:
Kit

It may be the display that is defective, or maybe just mis-wired.
If the display is not being initialized it will show only the top row 
of blocks.  Not being initialized can result from short or open 
connections to the EN, RS, RW, or any of the Data leads.  
Best test is to try another LCD display to see if the problem 
persists.  Since you can vary the contrast it would seem that 
the present LCD is probably working, hence the suspicion 
that an LCD control lead is not working properly.  A DVM or 
oscilloscope on one of the LCD control pins should show 
data flow during the initial turn-on period.  You have to look 
closely though because the leads will be active for a very 
short period of time.  If data flow is indicated then the Arduino 
is probably still good.

Arv  K7HKL
_._


On Thu, Sep 24, 2020 at 12:28 PM Kit Peters <popefelix@...> wrote:
Contrast control only makes darker / lighter blocks. Guess my Nano is hosed.

On Thu, Sep 24, 2020, 12:39 Evan Hand <elhandjr@...> wrote:

Kit
try adjusting the contrast control. If you can not get the display to show characters, then most likely the Nano is damaged.  Checking for the clock signals would not make sense if the Nano is bad.  The Nano programs the Si5351 DDS, so there may or may not be a clock frequency output. 


73
Evan
AC9TU



--
Kit Peters, W0KEH
GPG public key fingerpint: D4FF AA62 AFEA 83D6 CC98 ACE5 6FAE 7E74 7F56 ED1D
Hello to any and all NSA, DEA, or other government or non-government agents reading this email.  Tell me about your life; I'll tell you about mine.


Evan Hand
 

Kit,
I agree.  The Nano is the most likely failed device.  There are a number of things between the control header and the LCD display.

Arv,
I am not suggesting a new LCD, only a new Nano.  In the prior instances where this has happened, the Nano was the only device to fail.

I will state again, these are my opinions.  Please feel free to have your own, and to verify your choices.
73
Evan
AC9TU