No panel display

[bryanb...@gmail.com]

I finished the assembly.  Applied power.  Front panel power light on.  All three fans on rear panel operating; more loudly than I expected.  No display.  Waited 5 minutes.   Nothing.  Status LEDs on Arduino board operating.  Suggestions?  

[WA2EUJ]

It sounds like the Arduino isn't programmed??? It slows the fans down within 0.5 seconds of turning on.

At the bottom of the page is hex file, have you ever used xloader?

Here are instructions...

https://www.hobbytronics.co.uk/arduino-xloader

[bryanb...@gmail.com]

Okay.  That should be an easy fix.  However, I do not see the hex file posted

[bryanb...@gmail.com]

Successfully uploaded HEX file to Arduino.  No change.  Still no display, three small fans "screaming."

[patrick...@gmail.com]

Did you arrive at a solution to this?

I am encountering a similar issue where during the Front Panel Assembly, step 10 states that you should be able to connect the board to a PC via USB an the front panels should come alive. My LCD backlights come on, the status lights on the Arduino are lit, but the operating screens never display anything. I did manage to reload the HEX with XLoader, but no change.

[jcve...@gmail.com]

When we had this issue in the past, the pins on the sockets for the LDC's had not been trimmed and were shorting against components and traces on the Mega. The Mega is a 2560. The other thing to check is the solder jumpers on the LCDs, make sure they are there in the correct locations.

Jim.

[patrick...@gmail.com]

The pins were trimmed, with a flush cut, but I trimmed them even further. No solder bridges, no cold joints. Jumpers on the LCDs are in place, sb1, sb2, and sb3.  I don't see how they could be in the wrong location. Both displays are devoid of any output other than the backlight. There are two red LEDs on, steady, on the Mega.

Any test program for the Mega? Perhaps a means to test the Mega and a LCD off the PCB?

[jcve...@gmail.com]

Yes if you are familiar with Arduino. you can go to the Waveshare site for the 2.8" display:

https://www.waveshare.com/wiki/2.8inch_TFT_Touch_Shield

In the 'Arduino' section of the page, there's a link to the Arduino libraries and examples. You can plug the LCD directly into the Mega and run the demo.

73,

Jim WA2EUJ

[patrick...@gmail.com]

 I am not, but at this point all I have is a very expensive brick, so I suppose I should take the time to learn.

[patrick...@gmail.com]

So, Connected the displays directly to the Arduino, ran the sample programs, all was well. (But that as using the ICSP interface and I didn't remove the jumpers). I don't suppose that you have  a debug version of the code that  prints to the debug console? Might be helpful tracking the problem down. Are we certain that we can operate without any I/O other than the displays hooked up?   Note: neither display has any information on it when just hooked up to the USB. The fact that both are blank seems pertinent to me.

[jcve...@gmail.com]

Great job on the Arduino examples, I'm glad that you eliminated the Mega and LCD's from our list of suspects. I have verified that a working control board with a programmed Mega installed and two LCDs will display both screens with just a USB cable plugged in. The touchscreen controls also work.

So we're down to either the Mega isn't programmed correctly or there's something wrong on the control board. With the current state of the USPS I'd like to avoid mailing something at least for a week or so. I can email you the source code and you can try programming up the Mega from scratch.

Also try taking some pictures of the front and back of the control board with the Mega and LCD's removed and I'll see if I can spot anything.

Jim.

[patrick...@gmail.com]

I did reload the firmware (V3.1) earlier with XLoader (HR500 Autoloader repeatably failed, normal and Debug). No change. I am fixated on the not one, but both displays are not functioning. Just started looking over the schematic, but the only thing I see in common signal wise is SCL, MOSI, MISO,  LCD_BL & LCD_DC  (which makes me curious about CN7 and the jumpers). I will start ringing out these signal paths tomorrow while the sub-assemblies are still  out.

If you would email the source, that would be helpful.

Patrick

[patrick...@gmail.com]

I started the morning out by ringing out the display. Sure enough, no continuity from R34 on one board, and R36 on another. Redid these two jumpers, reloaded the firmware, and now it works. For anyone having this issue in the future, I recommend checking continuity between C7 and the jumpers. Obviously the jumpers indicated continuity, but the signal was not making it to C7.

Thanks for the help.

[patrick...@gmail.com]

Test procedure for jumpers:

With the  board positioned LCD facing down, jumpers on the right, socket C7 is located on the bottom left. (Signals are labeled on the PCB)

Test for continuity between SB1 and MISO (Pin 5)

Test for continuity between SB2 and SCLK (Pin 6)

Test for continuity between SB3 and MOSI (Pin 4)

[jcve...@gmail.com]

Great troubleshooting and I'm glad that you found the trouble. Thanks for the procedure, too.

Jim.