My coffee maker wont turn on
Many coffee makers use neon bulbs to indicate that power is on. These do burn out after a while, but replacement is usually somewhat difficult. In this case, the coffee maker still works; you just don't have the immediate visual indication.
Many of the urn-type coffee pots have problems with the power cord breaking where it goes into the pot. To fix this, you need to remove the bottom, cut the cord where it is broken (on the outside of the pot), strip it back to match the part of the cord remaining inside the pot and crimp on new terminals of the same kind used on the original ends. The hardest part is squeezing the strain relief clamp where the cord enters the pot to remove it, and putting it back on. Study it carefully as it you remove it from the cord so you know how it works. To avoid a repeat of the same problem (and buying a new cord), be careful not twist the cord or bend it too tightly at the strain relief. NOTE: one of the wires in the power cord has a rib on the outer jacket. This is the neutral wire. Make sure it connects to the same place inside the pot as the original neutral.
Other failure points are at the power switch, or (rarely) the heater element. I've seen a programmable coffee maker with a burned-out relay (magnetic switch in a black plastic box on the circuit board). The clock and timer worked, but the heater wasn't getting any power. That part is about $5.
The easiest way to identify the problem is with an ohmmeter. Start by removing the bottom of the coffee maker (unplug it first!). Identify the heater terminals (the heater looks like a small version of the one in your oven and has either screw or slip-on terminals). Connect one of the ohmmeter test leads to each heater terminal to measure the heater resistance (typically 5 - 20 Ohms). If you have a basic (non-programmable) coffee maker, turn on the power switch and measure the resistance from each terminal to each prong on the plug. You should read either nearly zero ohms, or the heater resistance plus not more than a few tenths of an ohm. If you read open to one prong of the plug, you are on the track. Trace where the wire from that heater terminal goes. If it goes to the power switch, check the resistance of the power switch in the on position. If the reading is more than a couple of tenths of an ohm, the switch has dirty contacts, or it's broken or burned out. If you have a good connection from the heater to the power line side of the switch, but you get open from there to the hot side of the plug, the power cord is bad. Likewise, if you get an open reading from the other heater terminal to the neutral side of the plug, the cord is bad.
Programmable coffee makers have a similar troubleshooting procedure, except that you have to check for live AC voltage with the pot plugged in - this is not something to try if you aren't trained in the safe way to do this.
Sep 09, 2011 |