Hi!
I am trying to boot a 7 years old RP4 and I suspect it is broken...
My setup is
- The Pi 4 Model B
- A 100W ugreen wall plug that charges my mobile phone just fine
Ah. The joys of USB PD specs.
100W is the maximum the PSU can provide. To get that it needs to output more than 5V and it needs to negotiate with the sink first.
The 4B doesn't do PD so it will be getting whatever your PSU supplies without it. That should be 3A@5V.
- A SD-Card that I created using the Ubuntu version of Raspberry Pi Imager for the Pi 4. I see both partitions (boot/root) and I can read from it on my Laptop just fine.
What happens
- The ACT LED flashes once - then nothing more from it.
- The red LED stays on.
Can I conclude that the Pi is broken?
You could but if it were me I'd look at The Boot Problems Sticky first.
Statistics: Posted by thagrol — Thu Dec 11, 2025 12:55 pm