Raspberry Pi has power but no Display

[/RaspberryPi]

Hello, this is my first time using a raspberry pi so please forgive me if I forget anything or mess up on explaining. I have recently been working on a summer research project with the goal of making a turtlebot waffle pi be able to do machine learning based driving as well as a few other tasks. I have build the waffle pi and was getting the raspberry pi ok board ready to run. I bought a micro hdmi to hdmi cable to connect it to a monitor in the lab.
Then I used the raspberry pi imager, from the pop_os shop, to burn it onto a SD card. Got it burned using the custom image from here and everything and whenever I turned on the raspberry pi. At first using the battery in board the waffle pi and then trying to just use a USB C wall outlet. Both times I do it though I get all lights, red solid and green blinking, but it does not display anything. I also mad sure to try both micro hdmi ports as well as going from dock to monitor as well.
I looked it up and everywhere I went said the lights are good. That the red is an indicator of power on and the green blinking means a application is running(from what I read usually the boot process) . From here I found out that sometimes you have to force hdmi output by modifying config.txt, but I am unable to do that as the SD card is read-only. I also made found online where some people have problems with the hdmi cord not being flush inside but I made sure it was completely in the hdmi port.
I also noticed that the keyboard and mouse I plugged in do not come on either. Is this just a power issue or is this where the raspberry pi is unable to boot. Any help would be appreciated. I have already went out and bought another SD card and had the dame problem and I was hoping to get some help before going for the third time.
Edit: After trying the classic turn it off and on again trick. I was able to edit config.txt from my laptop. Now it will turn on with the red light but the green blinking only happens for a second or two then stops.

submitted by /u/The_All-Father3
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