New Build (First Time) Problem with start up

Hello everyone, I am sorry that my first one is to ask for help. I have been an avid reader of this forum for several years and finally decided to build a heatermeter. After completing the build I attempted to boot it up and ran into a problem.

I attempted to add a video or pictures to better describe the issue but I don't have permission to add anything to my posts.

-The Board starts up and the LCD displays a random amount of forward slashes and I think "&" (it looks more like a person sitting down backwards on a chair with a semicolon) in random changing patterns much like "&//&/&/&/&////"
-This happens for about 10 seconds and then I get "Pit: 0F ^ 0%^" this only stays up for a flash
-Then the board goes into another set of random characters this time with forward slashes and a character with a three line block on the bottom and a single dash on the top
-After 35 seconds of this (I thought this was from it writing the wifi from config) it give me a screen of "??/??o? /o???/?"
-that screen freezes for 15 seconds and then I get a flash of "Pit: 0F ^ 0%^" again
-Then a blank screen for 2 sec and back to random patterns of characters and forward slashes that goes on indeff.

I attempted to connect through web but no heatermeter is found.
I started pressing buttons and it responded to pressing right button but only displayed gibberish of random characters

Board is Heatermeter 4.3 with w/Thermocouple PCB from store so the surface mount was tested
Raspberry Pi Zero v1.3 (no Wifi)
BINZET 12 Volt 2 Amp Power Adapter
Panda Ultra 150Mbps Wireless N USB Adapter

I would appreciate any help that could be offered or suggestions about were to begin troubleshooting.

Thanks
Dallas

So I went back and inspected every soldier joint to ensure I did not have any cold joints and that separation existed and could not find any problems. I also switched out the pi zero v1.3 with a pi B+ and received the exact same results although today with both pi and new sd card I was never able to get it to flash the line showing pit temp. Is it possible that I have a bad atmega chip?

I know that I have seen a post with pictures/diagrams showing voltages and continuity checks that can be performed. If someone knows where this information is located it would save me considerable time re-searching through old posts.

Thanks in advance for any leads as to were to investigate.

Sorry you're having problems but I am not sure what would cause the issues you're experiencing. Here are the voltage diagrams so maybe that can help you figure out what is going wrong

If you press the buttons and you see the screen changing or you see the leds turning on and off, then more then likely the atmega is ok,

I would make sure you don't have any continuity between your pi header pins

It is also possible that most everything is working but your wifi connection isn't being made for some reason, and you also have an issue with your LCD.
Two things I would do, first I would momentarily drop wifi security on your router and see if the HM connects (using the nifty preconfigured wifi connect download that you can get from heatermeter.com/dl). I could not get my zero w to connect no matter what I tried, then I dropped wifi security and it connected, after enabling wifi security again is still connects (go figure).
Second, I would look at the solder work on the LCD, the shift register IC, and the headers that connect the LCD daughter board to the HM main board. Once upon a time I had an LCD with flaky connections and I was getting crazy symbols on the screen as you describe. From the sequence of events you list it seems like the HM is functioning, at least at some level.