Was used after a period of time according to the magnetic field or voltage external factors may cause the false positives omission of solution is very good, generally are the problems of low and high sensitivity, VR4 adjustable can normal use, want to make the security equipment better service for your daily maintenance is necessary but little of that is, the article according to the 3800 + motherboard, supermarket, clothing, equipment security and maintenance methods.
The RF (radio frequency) system general fault judgment method:
1. Check the equipment power supply is working correctly (indicator is on), don't work, check the switch key, power plug, external power supply or whether insurance fuse.
2. The power supply is normal power supply equipment, can open the equipment to observe whether the substrate lights.
3. Open the receiving antenna surface cover, ?