On more then 1 occasion I've been woken up by my low voltage alarm going off on my Dx7 because I forgot to power it off after setting up a model, etc.. Other then a bind light on the back of the Transmitter, there's no power light to remind you that you've left it on. So after some research on the forums, this is the easiest way I've come up with to install a "Power On" LED. Step 1 is to remove the battery and the 6 screws on the back of the DX7.
Next step is to carefully unclip the antenna from the board and remove the 4 screws on the inner board.
. Next locate position "J5" on the board you just removed the 4 screws from. you'll notice i've already got the wires soldered in. Position 1-J5 is a positive and the other 4 are negative. With a meter I got 3.2 volts across here. Perfect for a 3.2 volt L.E.D.
. Solder a positive and negative wire from said locations as shown. Push through from front and solder on the backside of board. Again, youll notice ive already done this in the photo.
. Solder on an L.E.D. of your choice and choose a location for the L.E.D. Drill carefully! I decided to drill directly through the SPEKTRUM label on the top/ front of the TX. There is nothing in the way if you drill here. Then I just held in place with some hot glue.
. Put everything back in reverse and there you go!