【Repair】Fire emergency light fault inspection and repair
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A fire emergency lighting lamp that I disassembled before malfunctioned during use. As long as it was connected to the mains, the fault indicator light would always be on, and after the mains power was cut off, the lighting lamp would flash and go out. This time, we will further detect and repair this emergency light.
This time we are going to repair a faulty fire emergency lighting. [color=rgb (0, 0, 0)]G01 fault light is on G02 old battery P01 fault indicator[/ font] V01 production process
: Graphic part↓ 1. Repair preparation Material and tool preparation 1. One faulty emergency lighting lamp 2. One digital multimeter 3. Wire tools, etc. P02 Repair the protagonist 2. Repair principle 1. Principle From a previous disassembly article, we learned that this fire emergency lighting uses the CD4541BE delayed power-off switch chip. The design principle of this chip is simple, the peripheral circuit is small, and the failure rate is relatively low. So we start with other vulnerable parts, mainly transformers, batteries, LEDs, etc. When the emergency light is plugged into the main power supply, the fault indicator light is always on, indicating that there is a circuit or battery electric shock failure inside. After investigation, it was found that the internal nickel-chromium battery pack was bulging. The voltage measured with a multimeter was almost zero, so it was initially determined that the battery pack was faulty. It is necessary to replace the new rechargeable nickel-chromium battery and further test its function. After inspection, it was found that the nickel-cadmium battery inside was damaged and could not be charged. This time, try to replace a new battery pack to restore its normal function. P03 CD4541B 3. Repair process sharing First remove the outer shell screws and remove the cover to check whether there are obvious signs of damage or burning of the internal components, and then use a multimeter to further measure and judge: P04 Open the interior It was found that there was a black liquid on the surface of the nickel-chromium battery pack. It was suspected that there was a problem with the battery pack. After using a multimeter to determine whether it was a battery pack failure, the voltage was abnormal: P05 Battery Pack 0)] Take down the battery pack, cut open the outer layer of heat shrink tubing, and check the internal situation: ![]() P06 Cut open the tube An astonishing scene appeared. It turned out that the inside of the battery had been severely oxidized and carbonized, and the surface was covered with black unknown substances: P07 Battery Damage 1 The battery is completely damaged, which is the main reason why the fault indicator light is always on. Other problems need to be further checked after replacing the battery: P08 Battery Damage 2 P09 Battery Damage 3 Next, replace it directly with a new battery pack (3.6V): P10 new battery pack[/font ] Use high-temperature tape to add a layer of protection, wrap the positive and negative metal contacts, weld the positive and negative wiring, and then fix them to the original battery position: P11 Wrap tape After fixing it, close the lid and perform a functional test to see if it can be restored to normal: P12 Replacement completed Fourth, repair display Connect the emergency light after replacing the battery to the city power ~220V. This time the fault light is off, and the charging indicator light and the main power indicator light are on, indicating that it is charging and the basic functions are normal: P13 Connect to the power supply Unplug the power cord, all the indicator lights on it go out, and the two LED emergency light groups light up. Due to low battery power, the pipeline is slightly dark: P14 Unplug the power cord To ensure that the battery is fully charged, according to the label instructions, it is recommended to plug in the mains and charge the battery for more than 24 hours before putting it into normal use: P15 Emergency Lighting The function is normal after a long time test: P16 test is normal Emergency lighting function is normal, LED lighting effect is good: P17 Emergency lighting is normal V. Finally, something to say After inspection, the emergency lighting functions normally after replacing the new battery, and other electronic components have no faults. After long-term charging and multiple power-off tests, the emergency lighting is normal and can be put into normal use. END
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