Power, no boot

The only things I can think of are to make sure the ribbon cables are seated properly with their clamping bars also seated properly, and to make sure there is adequate voltage and current available to run the Pi and the display...

My setup which is only a Pi 3 and 7" display complains about the power if I don't use a high capacity power supply with an 18 gage cable.

Also some people have trouble with their SD cards, some cards (even new cards and cards that work on other computers) don't seem to work.

It is strange how few web sites have updated their material to indicate that the 7" display is compatible with the Pi 4.

Here is one site that goes through it...

https://www.softprayog.in/tutorials/connecting-7-touchscreen-display-to-raspberry-pi-4b

Hi Kyle,

Does the Pi boot OK and display when hooked up to a standard HDMI monitor?

I have a smaller touchscreen that required its own Kernal files.  This is because the display needed what is called a different Device Tree for Linux - which is fancy for saying the pins had to be configured to drive the display.

To see if this is the case, go to the manufacturers page and look for a hookup guide or tutorial for installation.  Here is mine just to serve as an example:  https://learn.adafruit.com/adafruit-pitft-3-dot-5-touch-screen-for-raspberry-pi

This was my process:

• Get the latest Raspian image to a SD card
• Hook up the raspberry pi to an HDMI ready TV and connect a mouse and keyboard
• Boot up successfully and follow all the prompts for initial set up including setting up WiFi and enabling SSH.  Shutdown.
• I could then go headless - meaning disconnect everything but the power cord and connect through the WiFi.
• I turned it on and used my PC with the program Putty to connect to the terminal of the Pi via WiFi.
• I cloned the manufacturers Kernal files per their instructions and ran their install script.
• Followed the prompts.
• Rebooted.
• Ran their calibration script for the touchscreen.

See ya',

Sean

Hi Sean_Miller

I read the installation instructions at Adafruit as you linked.

PiTFT no longer needs any custom kernels or modules, so you can continue to update/upgrade your Pi and it will work with the most recent releases.

Did you need a custom kernel for the device tree? Or did you need no kernel per your process steps?

I noticed there is an HDMI/Touchscreen mirror mode.  That could help you get closer.

PiTFT as HDMI Mirror (Best for Raspbian Full/PIXEL)

This option is the easiest to understand: whatever appears on the HDMI display will be 'mirrored' to the PiTFT. Note that HDMI is much higher resolution so it's not like it turns the PiTFT into a 1080p display. This is great for when you want to run OpenGL-optimized software, PIXEL desktop software, or really anything. The down-side is its a little slower than drawing directly to the framebuffer. You may not notice it but it's worth us mentioning!

If you have trouble getting it working in mirror mode, then dougw 's hints could be very useful.

I wish the adafruit page mentioned display-specific logs.

Is there anything in the output of

dmesg

related to this display?

Tony

I was referring to this quote on that page:

The PiTFT requires some device tree support and a couple other things to make it a nice stand-alone display. If you just want to get going, check out the following for easy-install instructions!

I thought it was doing something with the kernel, but it may just be the device tree overlay files.

I then used the instructions that followed assuming that is where the device tree overlay stuff was happening.  I definitely had no screen until I ran that stuff.

However, Kyle, you may not have an Adafruit TFT, so try to locate an installer similar to my experience from your manufacturer page.

See ya',

Sean

Hi Sean_Miller

I just now noticed you're not Kyle

My bad.

Diagnosing something that already works is not productive at all!

Tony

Looking at your profile, you are a newly minted Element14 member, a welcome to the site is warranted.

I suggest you start the Pi without the 7 inch screen just to simplify the equation. Remember that theory in Algebra. Simplify the equation before you try and solve it. A KVM with the Pi HDMI connected to a TV will get you video with minimal effort.

I have no experience with the NOOBs tool. I use an open source image hoeing software called Balena Etcher https://www.balena.io/etcher/ . Grab a full image of Raspbian operating system from https://www.raspberrypi.org/downloads/raspbian/  and use Ether to make an image to your SD card.

A boot up of the Pi with the new image will confirm 1st you have a working Pi. The same SD image can be used to support the touch monitor.

Sean is right on target. The smartest thing ANYONE ever told me (it applies to everything but it REALLY applies to computers)

START WITH WHAT YOU KNOW WORKS

Cant tell you how many times ive seen people put together a new pc wit all new parts, save the mouse. The spend HOURS assembling it even go through cable management and get it screwed back down before then plug it in

only guarantee there is frustration

strip back everything you can, then slowly but surely swap out the old stuff w/ the new.....