Pi wont boot [red light on, green light flashing]

[trustyhank]

New raspberry pi just came in, here is the info (im a noob, i'll try my best to give all the info)

1. This SD card: http://adafruit.com/products/102
2. This power supply: http://adafruit.com/products/501
3. Loaded the disk image via command line on OS X using this method
http://www.blogcdn.com/www.engadget.com ... termdd.png

When I connect power supply and hdmi cable [to telelvision with hdmi] the red LED lights up, as well as the top green one, which flashes occasionally for about 10 seconds and turns off. the red LED remains on. The display is black the entire time.

Not entirely sure where to begin trouble shooting, any help would be great!

[drgeoff]

You need to determine which of these two situations you are in:

1. The RPi is actually booting OK but for some reason your display is not reacting. A couple of ways to check this are a) boot with a TV connected to the composite video socket (HDMI not connected) and b) boot with a network cable between the RPi and a router with an active DHCP server. The LAN LEDs on the RPi should come on.

or

2. Your RPi is not booting. The most common causes are an inadequate power supply or an SD card that isn't written properly. If you connect the card back to your Mac again, what files can you see on it?

[trustyhank]

Thanks for the reply drgeoff!

So I bought a composite video cable, and it worked! The RPi booted completely, everything worked great. Any idea why the HDMI wouldnt be working? Thanks again

[Dilligaf]

put

hdmi_force_hotplug=1

in your config.txt file, it's on the partition you can read with your PC check out http://elinux.org/RPi_config.txt for other options

[saracb]

I was having the same problem with my raspberry pi. I tried a number of things including reformatting the SD card several times. I ended up reformatting with my digital camera and then using my ubuntu partition to copy over the img file using the dd utility. But still nothing - red light solid, green light flickers and then stops flickering.
I tried uncommenting the hdmi_force_hotplug=1 line in the config.txt file (opening as root) and it worked with my hdmi cable plugged into the tv. I was all ready to go out and buy a monitor as I am in the process of moving and don't have any monitors with me, but no need. Thanks for the advice, I'm glad I found this post!

[MyeahDaSeer]

I ran into the issues after successfully formatting the Micro SD cards. So I attempted to format the Micro SD, this time with the Logical Address Adjustment settings set to yes and it did the trick.

[rreboto]

I ran into another problem where the Raspberry Pi would simply stop booting right after detecting the `sd` device. Turns out I had copied `cmdline.txt` from another Pi and the `root=PARTUUID=xxxxxxxx-02` was wrong. Once I changed this to the ID of the actual card, it worked.

hth