Once the remote control receiver circuits are not working properly, you can distinguish fault from which part of the circuit as follows, that is, from high-level level upgrading a circuit or amplified, orthopaedic, Super circuit.
① checking when amplifying, shaping circuits, signal input/output point is to find the critical points of failure. Specific method is with remote control launches signal, with oscilloscope observation zoom, and plastic circuit has no signal entered (as LM385F of ⑤ feet), as has signal waveform, description high-level circuit, and Super again rose circuit basic normal, fault in zoom, and plastic circuit; as measuring not to signal, is fault in Super again rose circuit zhiqian: on zoom, and plastic circuit of check, can measurement LM358 of introduction feet voltage, and and normal control, if not normal, more for IC itself damaged.
II maintenance of Super-up circuit, you can check the DC voltage of the transistor, if not normal, check the DC bias circuit or transistor itself. DC bias voltage is normal, check the AC circuit, best for SMD Capacitors with a replacement method.
③ maintenance of high frequency amplifier circuit, also check high level DC operating point of the pipe first, then check the coupling element method, there is generally no harder to find fault.
Remote control receiver t at low voltage, low current circumstances, there was no burnt circuit board fault, transistors and integrated circuits of the failure rate is small. Highest failure rate in received frequency offset, mostly because of water or circuit board damp to make another circuit stop oscillating. To do more work on cleaning, flooding tide, measure voltage (waveform), removing as little as possible components. Car anti-theft system with of received device, regardless of is adjustable sense type also is adjustable capacity type, also regardless of is Division straight plug-in also is posted tablets devices or mixed way (resistance capacity components with posted tablets, transistor, and IC, and Electrolytic Capacitor with straight plug-in), they Zhijian almost completely can swap using, as long as found GND (grounding), and +V (power are), and OUT (signal output) end of corresponds to relationship, and again adjustment received device of received frequency can.