For a lot of newcomers the problem is not necessarily the SD card/installation, but rather the communication with your monitor (as Eric Wilson rightly asks above). Many people reuse an old(er) 'VGA' (or similar, SVGA, XVGA) monitor with the PC-style VGA connector, and then use an HDMI-to-VGA 'adaptor'. BUT there are 'issues' with this, that require you to edit your config.txt
file to force the output into the correct format.
Of course I cannot be sure that this is your problem, which is why we need to know what kind of monitor you are using. Even so, call this an 'educated guess', but you need to search around for 'Raspberry Pi HDMI to VGA' where you will find tons of people with similar problems, and various solutions. This stumps a lot of people, and it really deserves something of a 'Health Warning' - monitors have different requirements and the settings take some getting used to.
Tip 1: if you need to edit that config.txt
file, you'll almost certainly find it easier to do this back on your PC, editing directly from the SD card. HOWEVER you'll want to use a true plain text editor that will handle the line breaks properly, since Linux and Windows do this differently, ordinary Notepad can mess up your files, so you'll want to use a utility like 'Notepad++' which is downloadable on the web.
Tip 2: There's a discussion about this in a place you might not think to look - on Amazon where people are commenting about HDMI to VGA cables and providing some useful advice about Raspberry Pi settings, e.g.
http://www.amazon.co.uk/gp/aw/review/B0088K7QUQ/RE81S534DQ1CR/ref=aw_cr_RD64E946QD7M8?cursor=3&sort=rd
Tip 3: There's a basic discussion about the HDMI to VGA problem here:
http://www.raspberrypi.org/phpBB3/viewtopic.php?p=269212
and it includes the suggestion to edit the config.txt
file and UN-COMMENT the second of the following two lines when you find them (i.e. REMOVE the '#' comment symbol as the first character), which will force the output to come out on most VGA monitors, albeit at a very 'expanded' size, 640x480, but at least it will get you going:
# uncomment if you get no picture on HDMI for a default "safe" mode
hdmi_safe=1
Tip 4: Here on stackexchange there's a more thorough discussion about the various monitor settings:
https://raspberrypi.stackexchange.com/tags/config.txt/info
Tip 5: More great discussion, including how to find the relevant values for your monitor, on http://elinux.org/RPi_config.txt#Which_values_are_valid_for_my_monitor.3F
All the best - if I get some time I may try to provide a more user-friendly discussion of this headache.
Cheers, and let us know how it goes.
-Marc
OK
led flashes do you see? Is it only one or maybe there's more? The exact number is very important. Also, is this green led as bright as red led? – Krzysztof Adamski Apr 13 '13 at 13:53