No Defect Found (NDF) – Outside Lights

Some of the things that come to Repair Cafe Gosport aren’t broken but people don’t realise, however, a second person looking at the problem will often reveal this. This is a similar story, a relative asked me to help fix some outside lights they had bought but seemed to be faulty…

These lights are intended to charge during the day a glow at night, however, the owner had assumed they needed to switch on each time they should be used and turned off to charge. When I collected them I could see they had been left to charge, I switched them on confirming the perceived fault and took them home to investigate.

When I had some time, I investigated. I open the back cover, removed the battery and applied an external power supply, they worked fine.

Applying external power to investigate the issue

Then I put the photovoltaic panel under a bright light and measure the operating voltage. Then I realised the mistake I had made and my relative had made (the clue was in the earlier picture with the power supply attached) – the light only switches on when it is dark, therefore to test them it is necessary to cover the photovoltaic panel (or leave it upside down on the desk).

Light working

Just to be sure, I left them out in the garden for a few days to make sure they came on and charged correctly.

I have been reminded again before starting to dismantle an item or perform complex investigations, the first thing is to make sure the item really is broken and it is not simply a misunderstanding.

Repair Cafe Gosport events are on the 2nd Saturday of the month at MAKE Gosport. Book your broken item in by visiting