Re: PLZ HELP!!!
I don't use Eagle, but I can offer some common problems you could look at. When cad software places parts and traces on a schematic, they always snap to your grid point and if a symbol pin is on a different grid point from a trace end, they do not make a connection. I have used OrCad, PCAD, DxDesigner and PowerLogic and each one has the option to set your grid. Some people are tempted to set the grid point to a very small increment thinking they can get more information into a page. While this is true, in order to make sure the pin and trace hit the same grid point, you need to zoom in until you can verify the snap to grid. Once this connection has been made, then the connection will move with the symbol and stay connected. Since you said some stay connected and some do not, I would suggest you check this. Also, if you make a symbol and put a pin on an odd size grid, it may not be possible for the connection to snap to it after you put it on the schematic and then change the grid. What I do when I make a part is set my grid to 100 mil and place my pins. I can then reduce my grid to whatever I want when I draw the graphics for the part (opamp, usb conn etc). The benefit here is that I don't have to zoom in to place my connections and everything is on grid.