A while ago, my friend from Daily Dose Trier asked if I could fix their coffee tamper machine. Here, I’ll document the discovery process.
The machine had stopped turning on after two years of service, so the first step was to open it up and check for any obvious issues.
The machine itself is quite simple: a control board with a seven-segment display and three buttons (Pressure +, Pressure -, and Clean). Mechanically, it’s just a motor that presses the tamper plate down.
The control board looked fine—no burnt traces, and the only capacitor on the board seemed perfectly intact.
Next, I tried powering on the disassembled machine. Important to note: be cautious when working with live 220V here in Germany.
Still, nothing happened. I suspected there was a bad connection somewhere, so I checked all the connectors, making sure everything was properly plugged in (after unplugging it from the main 220V, of course). After reconnecting it, the machine still didn’t turn on.
It was time to break out the multimeter to trace where the power was being interrupted. Eventually, I found the culprit:
Yes, just a simple switch had failed. In fact, this isn’t the first time I’ve encountered a mechanical on/off switch causing a machine to become completely unresponsive. These switches are often the most used components, and when a machine doesn’t use high-quality parts (especially ones sourced from China), the mean time to failure (MTTF) is relatively short. Luckily, I had a similar switch on hand that fit perfectly.
The fix is done! Hopefully, this switch lasts longer in service than the original one.
I hope you enjoyed this short blog! See you next time 🙂