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Blank display on SBII

Don, ND6T
 

Trying to test SN144 and the display remains blank. I can turn the back light on and off, tune the VFO (and receive a signal) but there is no contrast.
I tried holding the Menu button for 4 seconds, released, rotated for more than 30 clicks Clockwise and...no display.
I tried holding down the Calibrate button for more than 4 seconds and less than 5, released and tapped the Menu button, waited for 5 seconds, pressed the encoder shaft briefly and turned off the power. When I re-power it just hangs (even while turning the encoder CW and CCW for more than 40 clicks each) until I press the encoder switch and then it starts but without the display. Without seeing the display it is difficult to tell where I am in the process. Quite blind.
Spent an hour doing this to no avail.
Looking at the vacant pins on the center-of-the-board end of the display (the non-connected end) I can see the correct voltages, data, and clocking except for the "Reset" pin (although I have good continuity from pin 26 of the '328). Perhaps the Reset only occurs on initialization?
Aside from me programming a new chip, is there any suggestions that could help me move forward? I have plenty of test equipment. This is my first experience with this display. Perhaps I should buy one, bread board it, and compare with the one on the SBII.
Is there a better way to do a factory reset?

Steven Weber
 

I knew I should have tested all these displays before shipping them.

 

The reset pulse only happens on initial power up.

 

You need to hold the function button closed for six “0ne thousand” counts to get into the contrast mode. Turn the encoder clockwise the increase the contrast.

 

The display is attached to the carrier board by the metal bracket. There is a piece of “zebra” meat between the actual display and the carrier board. If this bracket is loose, it might not be making good contact between the display and the carrier board. The connections are made under the wide part of the metal bracket towards the center of the SB board. Try pushing down on it near the center and see if that helps. You’ll probably have to cycle power when doing this as you don’t know which connections are causing it not to work.

 

If this turns out to be the problem, you’ll note a solder pad on the SB board on either side of the display near the top, to which you can use to attach a wire to push down on the top of the metal bracket.

 

Steve KD1JV

 

 

Trying to test SN144 and the display remains blank. I can turn the back light on and off, tune the VFO (and receive a signal) but there is no contrast.
I tried holding the Menu button for 4 seconds, released, rotated for more than 30 clicks Clockwise and...no display.
I tried holding down the Calibrate button for more than 4 seconds and less than 5, released and tapped the Menu button, waited for 5 seconds, pressed the encoder shaft briefly and turned off the power. When I re-power it just hangs (even while turning the encoder CW and CCW for more than 40 clicks each) until I press the encoder switch and then it starts but without the display. Without seeing the display it is difficult to tell where I am in the process. Quite blind.
Spent an hour doing this to no avail.
Looking at the vacant pins on the center-of-the-board end of the display (the non-connected end) I can see the correct voltages, data, and clocking except for the "Reset" pin (although I have good continuity from pin 26 of the '328). Perhaps the Reset only occurs on initialization?
Aside from me programming a new chip, is there any suggestions that could help me move forward? I have plenty of test equipment. This is my first experience with this display. Perhaps I should buy one, bread board it, and compare with the one on the SBII.
Is there a better way to do a factory reset?

 

Don, ND6T
 

Thanks for the prompt reply! No, that didn't help.
I've always called those "harmonica strips" ;-)
When adjusting contrast I get 3 bytes of clock on the display pin 5 (CLK), and on the pin 4 (DIN) I get what looks like a start, a data byte that is different from CCW or CW and a stop byte. On pin 2 (CE) I get just 3 slow pulses on each encoder click, the same for either direction. No change on pin 3 (DC).
Anything else that I can check? Looks like I need to do some studying on that display.

What a cheap education!

Steven Weber
 

Hum, DC is data/control select. It should be toggling at least once since first a control byte is sent, then a data byte. Check that connection.

 

For those are still waiting to start the kit, it’s probably a good idea to test the display before soldering it in. Friction fit the header into the pads by stuffing something under the loose end of the display. But make sure you are making good connections to all the pins.  

 

Also check to make sure the metal bracket around the display is solidly snapped into place to the carrier board.

 

Steve

 

 

Thanks for the prompt reply! No, that didn't help.
I've always called those "harmonica strips" ;-)
When adjusting contrast I get 3 bytes of clock on the display pin 5 (CLK), and on the pin 4 (DIN) I get what looks like a start, a data byte that is different from CCW or CW and a stop byte. On pin 2 (CE) I get just 3 slow pulses on each encoder click, the same for either direction. No change on pin 3 (DC).
Anything else that I can check? Looks like I need to do some studying on that display.

What a cheap education!

 

Don, ND6T
 

The mystery deepens. I reprogrammed the '328 (by the way, there is a comment identifier missing on line 405 of the sketch that is in the "files" section. No version numbers available) and that pin is now active. The data and clock pins are also going wild with activity compared to what it was. Still no response from the display aside from the back light working as it should.

In an attempt to return to "factory" reset I erased the EEPROM contents and now I have lost the BFO and VFO operation as well. Did you have something there that is necessary upon restart?

At least things are changing. That's headway, right?
-Don

Steven Weber
 

After a EE erase, it should go back to it’s original power up sequence of contrast adjust and then band select. The Si5351 doesn’t get initialized until you do those two steps.

-Steve

 

 

The mystery deepens. I reprogrammed the '328 (by the way, there is a comment identifier missing on line 405 of the sketch that is in the "files" section. No version numbers available) and that pin is now active. The data and clock pins are also going wild with activity compared to what it was. Still no response from the display aside from the back light working as it should.

In an attempt to return to "factory" reset I erased the EEPROM contents and now I have lost the BFO and VFO operation as well. Did you have something there that is necessary upon restart?

At least things are changing. That's headway, right?
-Don

 

Don, ND6T
 

I was hoping that was the case. Doesn't seem to do that.
Not wanting to take up more of your time I will order a new display from Amazon and, while waiting for delivery, try writing some test sketches to see what is going on. Maybe throw some serial monitor statements in to give me some "eyes" as to what is going on.
Thanks for the help. I'll let you know what I find.
Best 73,
Don

Steven Weber
 

Okay, I just tried the sketch I uploaded to make sure it was the right version. Except for having to add the “//” before 10Hz on line 401, it works on my board.

 

I also double checked the processor and display out of a kit which hasn’t been shipped yet and they both work as they should.

I guess you’re the lucky one.

 

-Steve

 

I was hoping that was the case. Doesn't seem to do that.
Not wanting to take up more of your time I will order a new display from Amazon and, while waiting for delivery, try writing some test sketches to see what is going on. Maybe throw some serial monitor statements in to give me some "eyes" as to what is going on.
Thanks for the help. I'll let you know what I find.
Best 73,
Don

 

Don, ND6T
 

I just realized that I had not tied up this string of messages. Please forgive me.
The issue was caused by a defective display. A new one, ordered from Amazon, performed just fine.
My groping about in the dark caused me further problems, though. When I "erased" the EEPROM settings upon re-loading the firmware I used the Arduino default of loading all zeros into EEPROM. Wrong! You need to load all ones for this firmware. Duh! Read the code, Don!
Dissection of the original display revealed a microscopic crack in the substrate of the LCD (not the carrier board). Likely it worked through any QC tests before it opened. The SB2 is an incredible rig. No one can tell that I am not using an Elecraft. AGC is superb. CW operation is a dream. This was a really fun build.