Testing of cell phone jammer at every frequency channel should be finished

The failure of the latter is known as delayed if the shutdown problem, and low-voltage alarm display black or non-display and the current is too large, the transmit path amplifier is damaged, circuit leakage faults occur simultaneously. Press the power button to boot, but can not boot or freezes at the same time, characters and key does not work. This failure is caused by the power control of the sealing off of the part of the software is not running properly. Display failure boot, the display no character display, black screen, the failure occurred the negative pressure generator to adjust the display contrast, display part of the integration process the data lines, CPU data lines connected socket, or screen damage. The cell phone itself has the anti-interference ability against  cell phone jammer  once it gets through a call.
Ericsson models, start an instant to observe the change of the display contrast control voltage, can determine the working status of the CPU, because the contrast control voltage is provided by the CPU a set of variable duty cycle pulse of rectified. Send and receive path failure the cell phone is switched to normal, we should first check the receive path is working properly. Motorola models in the SIM card is inserted before the bar graph of received signal strength indication, Ericsson models can be seen directly on the display bar graphs of received signal strength indicator. Nokia models insert the SIM card and transferred to the menu "Network Selection", to enter manually search the network function, and the receive path failure will appear on the display name of "China Telecom GSM network operators. The directional antenna information of  cell phone blocker should be described in details.
Such as faulty display "network service" message. Such as received signal strength indicator is the receive path failure. If the receive path is working, at the receiver IF section can be observed with an oscilloscope to the pulse signal of the cycle rules. GSM cell phone to send and receive channel failure must first rule out the receive path failure, and then exclude the transmit path failure. Because the local oscillator of the transceiver paths shared PLL; In addition, if the cell phone to receive part of the fault, does not receive assignment information received from the base war, send pathway will not be able to enter the ready state. Parts of the failure of the send path involves more contact with problems such as antenna, antenna switch. The directional antenna of  cell phone jammer contains 2 pieces of antenna plates.
IF filter, mixer, modem, A / D converter, the Capriccio change the circuit, the system clock problem, and the above-powered power supply filter capacitor problems. TV and dial numbers using a cell phone, interference on the TV screen point of view less than corrugated, then send pathway does not work, send pathway does not work, failure occurred in the power amplifier module is bad welding or damaged, send the pressure of the empty oscillator (TX VCO ) damage, power amplifier control module, power supply part of the fault. Earpiece, microcell phone silent and not to send, then measured with a multimeter handset microcell phone resistance value, replace the good parts. Testing of cell phone jammer at every frequency channel should be finished.
The failure generally occurs in the Ericsson multi-mode conversion module, voice decoding module and the module power supply part, addition the majority of the sealing off of the part of the circuit and damage will occur earpiece, microcell phone simultaneously with the entry into force. Ringer fault the fault occurred in the ring power supply part, the ringing of the driver transistor and protection diode, or ring to control the output of some of the damaged or loose soldering. All the keys do not work after the boot of the key disorders, Motorola models should first check the hands-free system, Ericsson models to check the pull-up resistor on the power FET switch keys online pull-up resistor, the key individual short circuit is the main reason. The signal emission performance of omnidirectional antenna of  cell phone jammer  is shown as follows.