The first task is to remove the battery from your Dx Transmitter. Then open the transmitter case. The Dx8 is more difficult to open due to it's case design. You may want to get some thin, double sided tape, from a craft or office supply store to replace or add new tape on the Dx8 handles. Next, remove the switch, which is much easier with a Spektrum Radio Switch Bezel Wrench designed to remove Spektrum nuts.
The above photo shows a support for the switch to minimize damage to the small wires at the solder joint. Also, be careful to not damage the antenna wire. The long handle on this switch makes it the most likely to break if your transmitter is dropped or falls over.
The above photo shows the factory solder joints and details of the factory installed switch. Be sure to note which color wire is nearest the top of transmitter before removing the broken switch from the case. Normally the red wire is closest to the top of the transmitter. If the switch is not replaced in the original orientation, the switch will work opposite to what's expected.
The Photo above shows a replacement switch from Digi-Key with the Spektrum retaining nut. The threads, dimensions, and electrical specifications of the Digi-Key switch, part number 360-3394-ND, are a good match to the factory switch.
The photo above shows wood blocks (short length of 2x4) used to support the switch. Not shown is a shop rag placed under the switch to cover transmitter electronics and avoid accidentally spilling solder inside the transmitter when un-soldering the old switch and soldering wires to the new switch. Also not shown is a pair of pliers with a rubber band on the handles used to support the switch when un-soldering and soldering wires. The pilers required larger support blocks and securely held the switches while un-soldering and then soldering wires to the new switch.
The photo above shows small diameter solder to avoid getting too much solder on the tip of the solder iron. Also shown is a solder sucker which is highly recommended to remove excess solder when un-soldering the old switch. This also avoids having to manually pull the wires loose from the switch and accidentally flicking molten solder inside the transmitter case.
The above photo shows an inexpensive soldering iron from Fry's Electronics that when set to 350 degrees C works well for removal and replacement of transmitter switches. A higher temperature setting on this iron is required for soldering much heavier battery wires to new connectors.
If you have questions or suggestions about replacing a Spektrum switch on your Dx9 or similar transmitter, please contact Webmaster.