Power on delay issue

Hi Guys,
First time ever posting on any forum whatsoever!
My son and I have built an arcade machine and a jukeboke using Raspberry pi 4B+. We have found that when we power the 240v powerboard that has the raspberry pi power cord and the tv monitor power cord attached, the tv will not pick up the Pi signal and always displays no signal on the monitor.

We have to open the unit, power the TV first, wait until it fires up and at a certain time power the Pi. We have tried looking for a delay module but nothing seems to be clear on whether it is what we are after. We would want power delay to the raspberry Pi so tv can fire up first (we think?) Or is there a code get around to delay hdmi signal from pi to tv? Or, Is there a purpose made module for this? Not overly savvy with solder yourself modules but would be willing if only option. But a plug and play would be ideal.
Thank you in advance.

The Raspberry Pi uses a VESA EDID communication protocol over the HDMI cable to determine what type of digital video signal to send down the cable.

My guess is that the Raspberry Pi software startup is too quick, and when it checks for an attached HDMI device it doesn’t find it, because the television is slow to start.

If it was on my lab bench, I’d enable wireless and SSH on the Raspberry Pi, make sure I can get to the Raspberry Pi from a laptop or desktop computer over a Terminal, get the problem to happen again, and then try to restart various parts of the Raspberry Pi OS, such as the display manager.

Once I’d identified which part of the software needs a restart, I’d either write a script to do that restart, or I’d add a several second delay to the start of that software part.

Getting technical, the parts of the software are managed by a program called systemd.

You could also write a new script that somehow checks for nothing being displayed and just reboots. Ugly, but may be effective if you can figure out exactly what nothing being displayed looks like from a software perspective in Raspberry Pi OS.

Alternatively, you might contact Raspberry Pi OS developers to report a bug “my pi does not display anything if it is turned on at the same time as my tv”, and see what they say.

Wow Quozl! Thats awesome information and enough to start investigating possibilities.
Thank you so much!