Broken circuit or LED?

[Coniferman]

More electronics than electrics but I am sure someone is more than clever enough.

Bought a Belkin inverter - has 4 blue LEDs to indicate the input power voltage. 1 of the 4 does not work properly and blinks on and off. I only paid a tenner for this thing so not going to bother with the hassle of returning it. I took it apart hoping to see a dry solder joint but although it looked slightly dodgy, additional solder has not made any difference. Nothing visibly wrong with any additional circuitry.

I was wondering if there is anyway to conclude if it is actually the LED or the circuit that's bad. I checked the voltage of the 3 working ones and got about 2.9V. The faulty one was fluctuating at lower voltages. I also checked its resistance (in situ) and it gave a different reading to the other 3. I do not know whether to conclude from that, if it is the LED or not?????

I could just try switching two leds around but my soldering skills are not brilliant so would welcome any conclusions/tests.

 

[P.S.]

if the unit actually works, leave it be i say

 

[Lectrician]

Or if you are picky, and have an iron......

Swap two LEDs over, or fit a new LED. They are pennies.

 

[Spark123]

Have you read the instruction book? Just wondering if it actually means something i.e. your voltage is genuinely fluctuating as opposed to a faulty LED.

 

[Coniferman]

Have you read the instruction book? Just wondering if it actually means something i.e. your voltage is genuinely fluctuating as opposed to a faulty LED.

4th LED 100% charge
3rd LED 75% charge
2nd LED 50% charge
1st LED 25% charge

Even when the other 3 are lit it is the 2nd one that is flickering so definitely a fault.