(from: LED Warning Flash Codes)
If a Raspberry Pi fails to boot for some reason, or has to shut down, in many cases an LED will be flashed a specific number of times to indicate what happened. The LED will blink for a number of long flashes (0 or more), then short flashes, to indicate the exact status. In most cases, the pattern will repeat after a 2 second gap.
| Long flashes | Short flashes | Status |
|---|---|---|
0 |
3 |
Generic failure to boot |
0 |
4 |
start*.elf not found |
0 |
7 |
Kernel image not found |
0 |
8 |
SDRAM failure |
0 |
9 |
Insufficient SDRAM |
0 |
10 |
In HALT state |
2 |
1 |
Partition not FAT |
2 |
2 |
Failed to read from partition |
2 |
3 |
Extended partition not FAT |
2 |
4 |
File signature/hash mismatch - Pi 4 |
3 |
1 |
SPI EEPROM error - Pi 4 |
3 |
2 |
SPI EEPROM is write protected - Pi 4 |
3 |
3 |
I2C error - Pi 4 |
3 |
4 |
Secure-boot configuration is not valid |
4 |
4 |
Unsupported board type |
4 |
5 |
Fatal firmware error |
4 |
6 |
Power failure type A |
4 |
7 |
Power failure type B |