Solar Lantern Light

[ramesh]

I am seeing a lot in the market with various designs all over to satisfy people, but these doesn't coming for a longer life. could somebody tell me how to over come this situation for life span in the future.

See here a lantern which I bought and struggling to light up after 5 months.
[attachment=o75]

[Annies]

i am facing a problem regarding this,the light is not turning off even i shutdown it. It is always glowing. Can you please tell me how to repair it...?

[admin]

The problem might be in the switch or the same wire connection, please check the wire from on/off switch where it might touches each other.

If the light is glowing using solar panel, then their could be another problem. please mention some more details so I can help you.

Does the light glows when you keep in sun?
Does the light glows when you keep in charge with electricity?

[ramesh]

I would say the problem is in the circuit board where the light is glowing from solar panel, but this should be off when it kepts under sun.

[srinivas]

The Problem: Why the Light Stays On Under the Sun
In your case, the circuit is failing at step 1. The automatic switch is stuck closed. Here are the specific components that likely have failed, in order of probability:

1. Failed Control IC or Transistor (Most Common - 90% of cases)
This is the "brain" of the operation. On the circuit board, you'll often find a small, black, 3-legged component (a transistor) or a slightly larger chip with more legs (a dedicated solar light IC).

What Happens: These components can be damaged by voltage spikes (e.g., from static electricity), heat, or simply wear out over time. When they fail, they can short internally, permanently completing the circuit to the LEDs, bypassing the day/night sensor logic.

2. Failed "Light Sensing" Component
The circuit uses the solar panel itself as the light sensor. However, some boards also have a dedicated Photoresistor (LDR).

What Happens: If an LDR is present and it gets damaged or dirty, it might always report "dark" to the control circuit, telling it to turn the light on permanently.

3. Physical Damage or Short Circuit on the Board
Water Damage: Look for green/white corrosion on the copper traces. This can create bridges where electricity flows where it shouldn't.

Poor Soldering: A bad solder joint could have cracked and is now making an unintended connection.

Burnt Component: Look for any components that are visibly burnt, cracked, or bulging.

How to Diagnose and Fix It
⚠️ Safety First: Disconnect the solar panel and battery before touching the circuit board.

Step 1: The "Cover the Solar Panel" Test
This confirms the problem.

Cover the solar panel completely with your hand or black tape.

Wait for 30 seconds.

Uncover it.

If the light behaves exactly the same (stays on) whether covered or not, the control circuit is definitely faulty. The sensor part of the system is being ignored.

Step 2: Visual Inspection
Open the lantern and carefully remove the circuit board.

Look for any obvious signs of damage: corrosion, burnt spots, cracked components, or bad solder joints.

Step 3: The "Direct Sunlight" Voltage Test (if you have a multimeter)
Set your multimeter to DC Voltage (a setting higher than 20V).

With the lantern in direct sunlight, measure the voltage across the two wires from the solar panel (disconnected from the board). You should get a reading of 5V to 9V, depending on the panel.

This proves the solar panel is working and providing the "it's daytime" signal. If the panel is dead, the light will always be on.

Potential Solutions, from Easiest to Hardest
Solution A: The Quick & Dirty Fix (Not Recommended Long-Term)
If you need a temporary light and don't care about automation, you can disconnect the LED's positive wire from the board during the day and reconnect it at night. This is cumbersome but confirms the rest of the light works.

Solution B: The Practical Fix for Most People
Replace the entire circuit board. You can find universal solar light circuit boards online (e.g., on eBay, Amazon, AliExpress) for a few dollars. They often come as a set with a new solar panel.

How to do it: Simply de-solder the old wires (battery, solar panel, LED) and solder them to the exact same places on the new board. This is usually the most cost-effective and successful repair.

Solution C: The Component-Level Repair (For Those with Electronics Skill)
This is only feasible if you can identify the faulty component.

Identify the IC/Transistor: Find the 3-legged transistor (often labeled SS8050 or similar) or the main chip.

Test/Replace the Transistor: If it's a transistor, you can try to test it with a multimeter's diode mode or simply replace it with an identical one (they are extremely cheap).

Replace the IC: If it's a dedicated solar IC (like a YX8018, QX5252, etc.), your best bet is to de-solder it and solder a new one in its place. This requires a fine-tipped soldering iron and some skill.

If you post a picture of circuit board then it might help for you to replace the faulty item.