LED lights gone dim but still flash bright

[osmiornica]

Hi, I have a common-uncommon problem. My Christmas LED lights have suddenly gone dim, except they flash bright occasionally (to their 'normal' state), so they still have the 'capability', just not all the time. They run on 220V with an EU plug that I use an UK adapter for, and they're indoors, so nothing has happened to them. They have 8 different modes, and they flash on the more 'erratic' ones, which makes me hope they're still salvageable because it's not the bulbs that have gone out. I took the cover off the controller, and one of the cables' smoldering seems to have burnt, but can't tell for sure. Can I solder them, is it worth it? They weren't expensive, but I hate throwing stuff away that could be fixed.
Here's a photo of what I think is the burnt part.
Thanks for any insight!

 

[kellys_eye]

Can't see anything burned but there may be a poor soldered joint that could make a difference if repaired.

As you state, these things are too cheap to take risks with.

 

[Morgann]

There are three reasons for this I know:
1, the circuit power supply is unstable
2, a certain component is broken, affecting the LED
3, LED internal structure problems, such as solder joint welding abnormality, this is a good solution, change the LED will know