One problem that I had was that I did the initial setup with NOOBS using the composite input. I found that upon the reboot after installing the OS I needed to be connected via HDMI in order to see the screen and proceed further. I don't know if that resembles your situation. If you aren't even getting the "four big pixels", that's where I'd start from. If you're connected via HDMI and having the same issue, you can get similar things where NOOBS knows how to talk to your display but the Linux needs a little configuration to do it. I'd be interested myself to see how to get back to NOOBS once you find yourself in a place where you have a keyboard connection but can't see anything, can't even see if there's anything to see. Maybe somebody will have a suggestion for that.
After doing so and a small amount of setup, I'm now able to connect to the device through SSH and so no longer need keyboard, mouse, or display. In fact, after getting a cheap Wifi internet adapter and another morning of effort, I am able to communicate with it without connecting it to anything but a USB battery pack (normally used for charging phones) and the Wifi dongle. Since I got it as a controller for breadboarded designs, this is just about perfect. The Pi and my circuit are connected to each other and not much else.
I found this:by Fnarg » Sat Nov 09, 2013 8:03 pm
Ok, so after a whole heap of trials and tests it seems like the culprit is the reboot function after all.
Using any form of reboot, through UI, through "reboot" or "shutdown -r" will cause the card to go haywire and refuse to boot again.
Using "shutdown -h 0" on the other hand works just fine.
So, next question, why?
It has been shown that after a shutdown some SD-cards need at least several seconds more to finish up. If you don't give them that time, but simply remove power before they are really ready it doesn't just damage the file system, but can also scramble the internal wear leveling bookkeeping functions of the SD-card. Oops!!!!
Apologies if this has been answered elsewhere:o)
I bought my son a Raspberry Pi for Chrsitmas and on Boxing Day we put the bits together. All went well and we installed Raspbian and he tried some coding. However, we had to move the Pi and so he shut it down. The Pi would not then restart. After looking on the Web we unplugged everything and left it overnight but still the Pi wouldn't work. I formatted a new SD card using SD Formatter and copied Noobs onto it. Success the Pi started up. We then installed Raspbian and waited for it to restart. Nothing happened, screen had no input and only red light showing on Pi. Can anyone help please?