[heero_yuy]

I'm an electronics engineer by trade so fixing these things, is for me, relatively easy. I don't know of a guide but there's probably something up on on Youtube.

Most of these modern lamps have a single NiMh battery, a 4 pin chip, a choke (coil), the solar cell, an on/off switch and some LEDs.

Most problems I've seen relate to corrosion of the battery holder/battery contacts or trouble with the on/off switch. A good clean of the first and some switch cleaner on the second or even shorting it out with solder do the job.

The batteries can and do die but replacements are easily sourced. I usually keep a look out for when Lidl do a promotion on rechargables as then they're much cheaper than the branded ones.

Only when they get much older do problems with the LEDs and corrosion of the solar cell connections kick in. By then the plastic parts of the lamp are usually getting faded and brittle.

For testing you can use a standard 1.5v battery instead of the rechargable one.