How to use a multimeter to measure leakage when the advertising light box is broken?
⒈My LED light box has two sets of lights that do not light up. What is the problem? Please let me know. Thank you.
1. Check that the circuit connection is correct. It will light up after power is turned on. Simple measurement method: use a multimeter for DC voltage. At 50V range, measure the voltage on one of the 1K resistors to be about 15-20V (pre ferably less than 18V). If it exceeds 20V, add a 1K resistor and measure until it is normal.
2. In order to facilitate testing, the controller pattern can be connected to the extended time interval state. At this time, the controller output is a large proportion of constant on and short off state. After the circuit is debugged, use a hot melt gun to seal the entire circuit with hot melt glue to pre vent circuit desoldering, leakage, and short circuit!
3. If the lamp set does not light up, use a multimeter at DC 250V. Connect the black test lead to each negative terminal of the controller (such as green wire, yellow wire, black wire, white wire, etc.), and the red test lead to the common positive terminal of the red wire of the controller. , if the pointer jumps at 200-220V, it means the controller is normal: the black test lead does not move, and the red test lead tests the voltage at both ends of each lamp bead in turn. If the voltage difference between the two pins of a certain lamp bead is very large or there is no voltage, it means that this lamp The beads are damaged, replace them and try again. According to the number of lamp beads, select a suitable resistor value and control the current of each channel to about 20mA.
2. In order to facilitate testing, the controller pattern can be connected to the extended time interval state. At this time, the controller output is a large proportion of constant on and short off state. After the circuit is debugged, use a hot melt gun to seal the entire circuit with hot melt glue to pre vent circuit desoldering, leakage, and short circuit!
3. If the lamp set does not light up, use a multimeter at DC 250V. Connect the black test lead to each negative terminal of the controller (such as green wire, yellow wire, black wire, white wire, etc.), and the red test lead to the common positive terminal of the red wire of the controller. , if the pointer jumps at 200-220V, it means the controller is normal: the black test lead does not move, and the red test lead tests the voltage at both ends of each lamp bead in turn. If the voltage difference between the two pins of a certain lamp bead is very large or there is no voltage, it means that this lamp The beads are damaged, replace them and try again. According to the number of lamp beads, select a suitable resistor value and control the current of each channel to about 20mA.
If there is no soldering, there may be some poor internal contact of some LEDs. It is recommended to replace these LEDs. The problem of replacing a string or checking the LED when it is not lit qq:815965016