Crystal CPU is the heart of the circuit, use it to provide a pulse signal (that is, the clock signal), there is this signal, the circuit controller (CPU, MCU), etc. to work. If this is broken, your remote control will not work. By the way, if you want to detect the remote control is not good, except towards TV (or other receiving device), you can also take over the remote control in any key, the alignment of the camera (the phone can be), can see luminous screen on the phone is good (of course, you should open the phone's photographic capabilities).
Crystal on the remote control is to determine the frequency, if it is a crystal with a remote control model aircraft, usually on top of the note indicated frequencies, such as 72.010, or 72M 11, this 11 refers to 72m away was the first 11 frequencies, 72.110. Now 2.4g high penetration of very small crystals. The following passage is taken from mx3g the most remote laji3865689 are relying on a specific frequency to send and receive signals. For example, there is a 72.810 crystal, so that the signal is emitted with a frequency of an electromagnetic wave from the transmitter prepared 72.810; also has a receiver with the frequency of the crystal, so that the circuit of the receiver only receives 72.810 electromagnetic waves, electromagnetic waves from other frequencies interference. If there is no crystal, the receiver can not receive any signal, because the outside world does not cause waves in the receiver circuit of "resonance" will be unable to control. Of course there are crystal-free receiver and transmitter, it is replaced by other circuits crystals. Furthermore, the crystal can not guarantee that the receiver will not be interference before the interference occurs, there will be a so-called "out of control."
