I have had some issues with my raspberry pi. I went online to find some videos to try to figure out what is going on. I then noticed that their raspberry pies Have the LEDs OK, PWR,FDX,LNK and 100 (in that order). My raspberry pi does not have those. Mine has ACT,PWR,FDX,LNK,100. Is it a different type of model? Whats going on?
THe ACT and the OK leds are the same thing.The name was changed in the revision.
From the raspberry pi website,
Two minor changes have been made to the silk screen:
D9 (Yellow LED) graphic changed from the incorrect 10M to 100 D5
(Green LED) graphic changed from OK to ACT (Activity)
So the ACT led signifies activity same as the older versions.
Hope it helps.
According to the elinux Rpi hardware page (search down for "5 Status LEDs"), the green D5 light is labelled "OK" on rev. 1 boards and "ACT" on rev. 2 (which is what you have).