Atten 858D+, the D stands for defective

A couple of years ago, I was looking for an inexpensive hot air soldering station to solder SMD components. It wasn’t the kind of tool I expected to use everyday, so the price point was an important factor for me. After a bit of research on the Internet I found this EEvblog video about the Atten 858D+. It looked good enough, and the price seemed right, so I bought it.

As you may have guessed from the title, I’m writing this post because it broke. After only a couple of years of occasional use. Yesterday I was soldering some components and it suddenly stopped melting solder. Looking at the display I saw the temperature slowly decreasing, and after a while the letters “H-E” appeared on the display, which I guess means “heater error” or something like that.

Left with a broken soldering station, I decided to open it to see what happened. The heat gun is relatively easy to open, just unscrew the plastic part covering the back of the metal tube, and undo two screws. Inside there is a small PCB with no components, used as a wiring board. Two contacts are marked “heater”, and unsurprisingly they measured open circuit. Disassembling the heating element was a little bit more difficult, as the metal tube is glued to the case, and the heating element is wrapped in mica paper and is a tight fit in the metal tube. After unwrapping the mica paper, I found a coil on wire, probably nichrome and a thermocouple towards the tip.

Actually, there was also something else. Two small pieces of wire stuck in the middle of the resistor coil, shorting some of the turns. And at one point, coincidentally exactly where one of the two extraneous metal wires was shorting the coil, the coil was melted, resulting in an open circuit.

In the picture above you can see in the red square the point where the heating element was broken, and in the yellow square the two pieces of extraneous metal wire that I removed from the heater coil.

The next question is: did those two pieces of wire end up there as a mistake, or were they put there on purpose to cause hot spots in the heater so as to make it fail prematurely? Is this a case of planned obsolescence? In any case I’m not going to buy Atten branded stuff again.