Broken desk lamp

The Major arrived at my door with a desk lamp in hand stating that it was not working and pointing to a frayed cable.

The lamp was a gift for one of the tykes a few Xmases ago. It is a flexible spot LED design from Ikea (sold under the name Jansjö, but not any more), nothing particularly complex.

Ikea Jansjö flexible LED desk lamp - Non-functional

The issue was that the cable had almost completely broken off. Not sure how, one of the furry friends may have taken a liking to it or it might just have been abused by one of the tykes.

Damaged cable

In the same manner as an LED light bulb, the lamp needs the mains AC rectified into a low power DV voltage (4 V / 0.75 A in this case), which is taken care of in a wall wart. Rather than using a captive cable (cheaper) the lamp has a moulded 2-pin plug (above) . Presumably this allowed Ikea to buy a shed-load of wall warts, at a heavy discount, that they could pair with any LED lamp in their range.

I had not come across this particular type of plug before, but a little searching gave it as a DIN 41529, most commonly found on speakers of a certain age. DIN or Deutsches Institut für Normung is the German equivalent of the BSI and the 41529 standard, since withdrawn, specified connectors for loudspeakers. Fortunately they are still available for very little (~£0.50 a piece). But in this instance I raided a friends spares box for a replacement.

Should be a straightforward repair, just cut off the old plug and wire a new one on....

Repair of DIN 41259 plug

Of course it slipped my mind until after I had snipped off the old plug that the LED would be polarised and so would only work with the wires connected in one orientation, doh!. However it didn't take too long with the multimeter's diode function test to work out which side of the cabling was connected to the positive diode terminal.

A pity then that it didn't work once rewired. A bit more disassembly to check for other faults, such as a dodgy switch or another broken wire, gave nothing and try as I might I couldn't get into the LED housing (although, as I found out after the repair, it is possible - see the second picture here). So I decided to try the connection the other way round (risking it blowing I realise) and,

Ikea Jansjö flexible LED desk lamp - Functional

let there be light. After that it was just a matter of re-assembling it and marking it.

JOB DONE

Time: 10 mins (plus 40 mins headscratching)
Cost: £0.60