Resistor Identification?
Logistics Pro
Joined: Nov 2004
Posts: 4,562
Likes: 2
From: Southern MD
I hate to discourage but so many things affect the components on a printed curcuit board such as a shorted diode, or higher than allowed load, even down to a micro proccesor gone south. I' am really not all that much when it comes to this stuff but I had a electronic controlled washer that was not very old when the curcuit board went out and was told this happened fairly often to these type's of machine.
After a failed attempt (lasted about a week) to repair the board I cross referenced the machine and found it also came out with manual controls to which I changed it out to. All I know for sure is that washer worked for a long time and still worked when I sold it.
After a failed attempt (lasted about a week) to repair the board I cross referenced the machine and found it also came out with manual controls to which I changed it out to. All I know for sure is that washer worked for a long time and still worked when I sold it.
Same here. Sears Kenmore Elite, if memory serves me.
There is one resistor on the board that is way too small (1/4 watt instead of the needed 1/2 watt.)
I've replaced that board twice in 4 years, for $65.00 a pop!
I'm gonna replace the resistor with a 1/2 watt and see what happens.
We're always close by when the washer and dryer run. (It's usually me that is closer. I wonder how she does that?)
Cargo Master
Joined: Jan 2004
Posts: 2,512
Likes: 8
From: Cook Forest and Irwin PA
thinking about the circuit for a moment, lets recall our 'pies' and 'eirs' (ears)
P=IE, power = current times voltage
E=IR, Voltage (E) = current times resistance.
P can be no more than .25 (1/4 watt)
R = 39 ohms.
Current can be expressed as Voltage over Resistance.
substituting into the power euqation:
P = E/R*E, therefore P=E^2/R
E^2 = P*R
knowing what we know, E^2 = .25*39 = 9.75, square root of this is 3.12 volts
check our work, 3.12v/39 ohms = 80ma
80ma * 3.12v = .2496watts
so now, turn on this thing with no resistor and measure the voltage presented at either end of the resistor, with respect to ground.
Bigger than 3.12v, go looking for why
P=IE, power = current times voltage
E=IR, Voltage (E) = current times resistance.
P can be no more than .25 (1/4 watt)
R = 39 ohms.
Current can be expressed as Voltage over Resistance.
substituting into the power euqation:
P = E/R*E, therefore P=E^2/R
E^2 = P*R
knowing what we know, E^2 = .25*39 = 9.75, square root of this is 3.12 volts
check our work, 3.12v/39 ohms = 80ma
80ma * 3.12v = .2496watts
so now, turn on this thing with no resistor and measure the voltage presented at either end of the resistor, with respect to ground.
Bigger than 3.12v, go looking for why
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