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PCB Help: Need to make new dial or short out for coffee grinder Answered

I just followed a great post to hack my Delonghi Coffee Grinder here: http://ping-pong-balls.blogspot.ca/2012/03/so-youve-bought-delonghi-kg89-how-to.html

However in the process I shamefully snapped off one of the knobs and part of the circuit board attached to it snapped. I'm wondering if there's a more or less easy way to fix this, such as a short circuit around the timer, or perhaps even create a new makeshift dial.

I'm a PCB novice, so any tips or re-directions would be great. Thanks!



5 years ago

Thanks for the quick replies! I ended up taking it to a local electronics repair shop. The guy just took it and worked on it for an hour and gave it back without asking for any money! Here's to generosity and grace! Sorry if taking it to a shop isn't a thrilling DIY story, but it's a great true story.

He had to basically short the section of the board that held the potentiometer as well as a couple of the safety switches (at my request).


5 years ago

Oh boy that knob, or potentiometer, is totaled. It would be possible to remove it with a soldering iron and replace it with a new one, but it might be hard finding a new one that would fit into the case.

You'll probably need a 10k Ohm variable potentiometer like this one: http://www.radioshack.com/product/index.jsp?productId=2062354&filterName=Type&filterValue=Potentiometers#. I'm guessing that 10k is the correct value as it is commonly used for control knobs. To be absolutely sure of what the value should be, you will need to find an identical machine with a working knob. You could then use a multimeter to test the undamaged potentiometer's value. Write the author of that blog post and see if he will test his knob's value for you, or see if it has the value written on it.

Are you able to do the solder work yourself? If not you may be able to find someone else to do it for you at a school or hackerspace.

if you're talking about the round bit with the 3 tabs in the center towards the bottom. that looks like it used to be a potentiometer...do you still have the other part of it? does it have any writing on it? someone else might be able to identify what type/size potentiometer it was and suggest a replacement. you'd just need to solder it back in where the old one was after removing the bits that got left behind.