About this item 

• 【Professional Multi- Functional Tester】This multi tester can perform accurate constant current driver board testing, TV backlight strip testing, and real-time detection of voltage and current of various electronic components with high-precision voltmeter and ammeter. It supports automatic + manual dual mode for voltage and current adjustment, and is also suitable for repairing all LED lights, and can judge faults intuitively (voltage=0 for short circuit, voltage=330V for open circuit).
• 【Stepless Adjustment & Safe Testing】This tester has the core advantages of safety and reliability: it is designed with anti-electric shock, no sparking when short-circuited, and intelligent adjustment of output voltage and current. It adopts dual isolation protection of power supply and tester, which can be tested for a long time without damaging lamp beads. No risk of burnout when testing single LED beads with wrong polarity. (Set voltage around to 20V and the current switch to 1mA)
• 【No Screen Disassembly Required】This backlight tester can test constant current boards, truly achieving comprehensive screen-free testing. It is equipped with factory default settings (330V/50mA) for direct use without repeated adjustment. Manual voltage and current control functions allow for precise range customization, enabling manual adjustment of the test voltage (0-330V/DC) and current (0-150mA) ranges. It can quickly locate backlight faults without blind replacement of the whole board, save maintenance time and cost, and reduce the risk of burning LEDs and screens.
• 【Used in All LED Lights Repair】Multi-Functional Tester can test all of LED lights, supporting all sizes of LED TVs, monitors and computer screens, and compatible with all high-voltage and low-voltage LED strips, including LED strips, LED panels, single LED beads, COB lighting sources, TV backlight, displays, computers, and various electronic components and more, making it an essential tool for LED light repair, TV backlight testing, and vehicle LED testing. It will not burn LED beads and panels during testing.
• 【Electronic Component Withstand Voltage, Breakdown & Characteristic Tests】Add 1mA precision wide voltage (0-330V) constant current source output, allowing for the development of various ingenious applications. For example, it can be used to measure the forward and reverse voltages of diodes, Zener diodes, transistors, MOSFETs, etc., and the withstand voltage or breakdown voltage of capacitors below 330V, varistors, TVS transient diodes, etc.
  
  
  

  Manually stepless pre-adjustable open-circuit voltage (6-330VDC), intelligently and automatically adapts to LED light source voltage during testing, requiring no adjustment!

  When the output voltage is preset to 20V or below, the 1mA current setting allows offline testing of various IC power supply pin voltage parameters, easily determining IC quality and ensuring no lamp burnout even when connected incorrectly during single-chip testing!

  Manually stepless pre-adjustable maximum short-circuit limiting current (3-150mA), intelligently and automatically adjusts the current during testing.

  Safely supports ultra-high voltage illumination for both high-voltage and low-voltage LED strips.

  Includes a 1mA precision wide-voltage (0-330V) constant current source output, allowing for various ingenious applications. For example, it can be used to test the forward and reverse voltages of diodes, Zener diodes, transistors, MOSFETs, etc., and the withstand voltage or breakdown voltage of capacitors, varistors, TVS transient diodes, etc., below 330V.

  

  Test Method of Constant Current Driver Board

  Testing situation: The LED strip of backlight is on with the tester, but it does not work with the constant current board;

  1. Cut off the power of TV, unplug the interface sockets of the constant current board and light bar;

  2. Connect the constant current board with the tester using the cables in the kits on right polarity.

  3. Insert the Red and Black pens of the tester into the anode and cathode of the interface of the LED light bar.

  4. Turn the power of TV on.

  5. Testing voltage ＞30V, Current ＞30mA and keep stable, and the LED strip working normal, then the Constant current board is normal.

  

  Product Testing

  • Test TV LED Backlight

  • Test TV Constant Current Board

  • Test Single LED Bead with Low Current

  • Test Single LED Bead with High Current

  • Test LED Lamp Panel

  • Test LED Integrated Optical Source

  • Withstand Voltage Test of Triode

  • Test LED Strip

  

  Product Overviews

  · MODEL : KT4H

  · Vin: AC 85-265V

  · Vout: DC 0-330V (Automatic / Adjustable)

  · Voltmeter Accuracy : ＜ (±0.5 ± 1%Vout)

  · Current: 0-150mA (Automatic / Adjustble)

  · Constant Current Board Current : 0-999mA

  · Ammeter Accuracy : ＜ (±2 ± 1%Iout)mA

  · Pin : 50VA (MAX)

  · Temperature : -20℃ - ＋40℃

  What‘s in box : 1* KT4H Multi-tester, 1*Test probe, 1*Power cord, 1*Socket cable, 1*Connection clip, 1*Bag, 1*User Manual

  FAQs:

  Q: How do I test a constant current board, and is it effective?

  A: The most important parameter for a constant current board is stable output current. However, the output must be connected to a load with a matching voltage. Therefore, connect the constant current board's output to the constant current input interface of the KT4H tester. Connect the tester's output to the positive and negative terminals of the LED strip via multimeter probes. Then, power on both the tester and the constant current board. The tester will display the current and voltage of the constant current board. If the current is stable, the constant current board is working properly.

  Q: Is this multi-functional tester accurate for testing LED strips?

  A: Yes, it is accurate. It can test and diagnose both single and multiple backlight groups without disassembling the screen; it can also safely handle both high-voltage and low-voltage LED strips. In addition to the basic functions of a tester, this multi-functional tester also includes constant current board testing and stepless current and voltage adjustment.

  Q: How do I test the quality of a TV with a single LED strip?

  A: This KT4H tester can perfectly solve the backlight testing problem for TVs with a single LED strip. The problem is determined by testing the constant current board. If the constant current board is normal, then the LED strip is definitely faulty.

  Q: My TV backlight flickers and then goes out. Can this tester determine if the problem is with the constant current board or the LED strip?

  A: Testing only the LED strip cannot confirm whether the problem lies with it. Testing the constant current board simultaneously will provide a more accurate diagnosis.

  Q: Will connecting the LED strip backwards burn out the LEDs?

  A: No. The main purpose is to check the current value of the LED strip.