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LED, or LED lamps have recently entered our lives widely. And this is not surprising, since they have many advantages compared to other sources of artificial light.
Here are a few of them:
1. Profitability.
2. Durability.
3. Security.
Both the price and quality of these lamps may vary, depending on their manufacturer. They are not very different in design, the components are the same, but the difference may be in quality.
This is especially true for the LEDs themselves and the cooling system. Although the lamp does not overheat much, heating is still present, which adversely affects the electronics.
Therefore, breakdowns of these devices also occur. This is very unpleasant, especially when the lamp did not last even a couple of months. Nevertheless, do not rush to throw it away, There is a way to repair the lamp, thereby saving your money.
Here, in the photo, a medium-quality lamp.
LED lamp repair

One fine day, it stopped working, although the lamp itself was fully operational.
It is clear that the problem lies precisely in the lamp, more precisely in one of its components.
So, let's proceed to repair the lamp.
To disassemble it, you must remove the diffuser.
LED lamp repair

Below it is an LED panel and an electronic converter. The diffuser can be latched or threaded.
This lamp uses a threaded connection, and this is the best option for the possibility of repair, since it does not require special efforts and special tools for dismantling.
Just scroll it counterclockwise and the matte cap can be removed without any problems.
Under it, as already described above, there is a panel with several dozen LED elements.
LED lamp repair

To begin with, you can look at the external state of each electronic component on the converter itself.
LED lamp repair

LED lamp repair

Sometimes the cause of the breakdown may be in it. Most often, this is a bloating of a large capacity electrolytic capacitor. If traces of deformation are visible on its upper or lower part, then it is definitely necessary to change it.
Also, on this board there may be a normal fuse, which could blow out due to a voltage drop. Then the problem is solved by replacing it.
If no external defects are detected on the converter, measure the voltage at its output. This can be done with a multimeter or a simple DC voltmeter.
LED lamp repair

LED lamp repair

By the way, you can measure the voltage at the output of the converter without removing the LED panel. This should be done on the two wires leaving the hole. But first, you need to insert the lamp into the socket of some kind of table or other lamp.
LED lamp repair

As the voltmeter shows, the output voltage is approximately 132 volts. And this means that the converter itself is in good condition and the problem is precisely in the LEDs.
LED lamp repair

So, as their connection is serial, failure of at least one of them will lead to complete inoperability of the entire panel.
How to find one that is defective? If outwardly this is not visible, there is an effective method to find the problem diode.
We put the multimeter into the dialing mode and connect its probes alternately, in parallel with each LED, moreover, the positive (red) probe of the device must be applied to the “-” pin.
LED lamp repair

On the panel diagram, the minus sign is not indicated, only the plus sign is marked. Therefore, not marked, and there is a cathode.
LED lamp repair

LED lamp repair

If the LED is working, when connecting the probes to it, a weak glow appears. That element that does not light up is faulty.
LED lamp repair

Next, remove this LED by picking it with a thin screwdriver.
LED lamp repair

After, gently tin its seats.
Now you need to find the LED to replace the burned out.
For this purpose, any working element is suitable, for example, from a flashlight with a problem battery or even from a lighter with a backlight.
LED lamp repair

Now where they just do not apply, so this should not be a problem.
LED lamp repair

LED lamp repair

In the same way as when searching for a fault, we find the positive and negative conclusions. Now solder the new LED accordingly to the polarity on the board.
LED lamp repair

LED lamp repair

It is seen that when a voltage is applied to the lamp, its glow occurs.
LED lamp repair

LED lamp repair

Thus, the repair was successful and the lamp can last a few more months, and possibly years.
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Comments (11)
  1. Leonid Zagain
    #1 Leonid Zagain Guests December 6, 2017 08:26
    3
    Yes, the author is absolutely right, I have been repairing this way for more than six months now! And yet, I wrote out aliexpress 100 LEDs for 89 rubles and now I swear them, even the lamp power does not decrease.
  2. Guest Sergey
    #2 Guest Sergey Guests December 6, 2017 18:05
    6
    The method is of course effective and maybe it will help someone, but it’s bad luck - not all LEDs ring like that! I have lamps and in them there are LEDs in each of which are several crystals ... They do not want to ring and light up. On one lamp, even a 25V PSU failed to light a single LED. And how to replace them ???
    1. Guest Alex
      #3 Guest Alex Guests January 1, 2018 15:24
      4
      It is clear that LED needs 2.5-3 only to open its transition.
      Take a source of 10, 15 volts and through a 1 kΩ resistor call so much of 3 crystals (for a glow). Observe the "+" and "-" !!!
      Old testers C 43XX were with a 4.5 V battery and lit any diode (in the resistance measurement mode).
  3. Vladimir Mikhailovich
    #4 Vladimir Mikhailovich Guests December 8, 2017 07:10
    3
    In cheap lamps, they never put any radiators as in the photo, and 99% of the faults are precisely due to the electronic power supply. For five years of working with lamps, not a single LED has died, but the intensity of the glow changed significantly, which was the reason for replacing the LEDs. The main trouble with cheap lamps is that the declared power is several times higher than the actual one. Depending on the manufacturer, it can range from 2 to 5 watts per 7 watts. a lamp.
    1. Valery Ratnikov
      #5 Valery Ratnikov Visitors January 1, 2018 00:02
      2
      It's right.
  4. Guest Valery
    #6 Guest Valery Guests January 2, 2018 10:02
    1
    please tell me the power supply circuit on the finger-type elements of an 18-LED lamp, it used to work from the battery and was charged from the 220v network (screwed into the mains cartridge), the battery died, the emergency source is needed in the countryside, thank you in advance.
    1. popvovka
      #7 popvovka Visitors January 5, 2018 09:40
      1
      Take 3 AA batteries (preferably Ni-Cd, but Ni-MH is also possible) with a capacity of at least 1000 mAh. Connect them in series and install instead of the old battery. This is all true if you had a small lead-acid battery.
      1. popvovka
        #8 popvovka Visitors January 5, 2018 09:48
        2
        If you have questions, write to
  5. Uncle Vitya
    #9 Uncle Vitya Guests April 24, 2018 16:22
    15
    To find a dead LED, I short-circuit each diode with a 20-50 ohm (1-2 W) resistor on the switched on lamp. On which lamp lights up, that one must be changed.
  6. Doubting Thomas
    #10 Doubting Thomas Guests November 18, 2018 19:14
    1
    I use a 24V power supply to find faulty LEDs. In the gap of the probe wire, I insert a resistance of about 1K, and parallel to the probes I connect a digital voltmeter. Resistance limits the current through the LED under test, and a voltmeter allows you to find working, but fried LEDs, in which the voltage will differ. Recently, I was repairing a group of identical bulbs where a microcircuit was used, which should give a current of 100mA, with a voltage of 30 to 70V. But the Chinese reduced the capacitance of the capacitors, as a result, the current increased to 150mA, and the LEDs were very hot, and burned out. I had to pick up the current-setting resistance. According to the datasheet, it is 3 Ohms, the Chinese have 7 Ohms, but really, to get 100 mA you need 12 Ohms ...
  7. hippopotamus
    #11 hippopotamus Guests December 4, 2018 2:44 p.m.
    4
    Schematic implementation of the lamp driver - current stabilizer, i.e. regardless of the number of LEDs connected in series, the current will be unchanged. hence the consequence - instead of a burnt-down LED, we solder the wire jumper and put up with a slight loss of brightness, instead of practicality.

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