Pi 400 doesn't work. Moderators: adafruit_support_bill, adafruit

[Einnovoeg]

I received the raspberry pi 400 and it seemed to work fine. I put it away for a bit and tried to use it and it wouldn't turn on. I'm using the official raspberries pi power supply. I've tried several other SD cards with different images, however the power light stays on for a few seconds and then turns off for a few seconds and then turns back on. No image comes on the monitor when connected by HDMI micro port. Please advise. Thank you.

[mikeysklar]

Which port have you plugged the display into. There is a HDMI0 and HDMI1. The left-hand connector (when facing the back connector panel) is HDMI0 which you want to use.

When did you purchase the Pi400 from Adafruit?

Is there anything else attached the Pi400?

Can you try powering another device with the USB-C power supply to confirm it is working?

What are the LED colors and patterns?

When booting from an SD card, the Raspberry Pi's green ACT light should have an irregular blink. However, it can blink in a more regulated manner to indicate a problem:

3 flashes: start.elf not found
4 flashes: start.elf cannot launch, so it's probably corrupted. Alternatively, the card is not correctly inserted, or card slot is not working.
7 flashes: kernel.img not found
8 flashes: SDRAM not recognized. In this case, your SDRAM is probably damaged, or the bootcode.bin or start.elf is unreadable.

[Einnovoeg]

Which port have you plugged the display into.
HDMI0

When did you purchase the Pi400 from Adafruit?
March 14, 2022

Is there anything else attached the Pi400?
The behavior is the same regardless of what is connected. Monitor or Keyboard and/or mouse connected or disconnected has no effect.

Can you try powering another device with the USB-C power supply to confirm it is working?
The power supply works perfectly with my other Raspberry Pi 4's

What are the LED colors and patterns?
There are no colors/patterns. When plugged in the solid green light comes on and stays on for about 18 seconds, and then it goes off. It stays off for about 3 seconds and then process repeats. This behavior is the same regardless of the SD card inserted. Nothing I do changes the described behavior. I have a every model raspberry pi and I have never seen similar behavior.
I believe this particular device is defective. Please advise.

[mikeysklar]

Thank you for verifying the power supply works with your other Pi4 models.

In the different builds you have tried were any a current Pi OS release?

I've not seen the long green (~18 second) scenario you describe. Normally hardware errors have the brief short / long flashing patterns. You can contact support@adafruit.com inquiring about your situation, but the normal policy is 30-days.

[Einnovoeg]

Yes, I tried the current build. I emailed support and they told me create a forum post.

[mikeysklar]

You can provide this forum link to support so they can see that we have discussed it. You are outside our standard 30-day warranty, but not by a lot so maybe they have some thoughts on resolving this for you.