Electronics Issue Burnt Looking Resistor Whats It Mean

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Maheel

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one of my other addictions is coffee (and associated machines)

i have a machine that wants to over fill and flood the boiler
i have switched out the fill solenoid with a spare and checked all the wiring etc and still floods...

i pulled the control board and it has this burnt looking resistor
i get a resistance reading of very nearly the same as the others when in place

the fill probe circuit is actually coming in on the bottom board on those black plugs you can see behind the bottom green plug
so this resistor may be un-realted to my issue ?

should it be replaced while i am in there or leave it alone

also, do resisters burn out or is something else causing it to "burn"

cap.jpg
 
Maheel,

That looks pretty ordinary. I'd be swapping that out and investigating the cause. Resistors normally don't just 'wear out'. There will be a certain percentage that fail like any other component, but it is likely that something else might be drawing a bit too much current causing that resistor to fail.

Leary
 
There was a bunch of really dodgy capacitors that got churned out by some cheap Chinese company many years ago and they managed to continue selling them and are still used in heaps of electronics today.

My old Tele was an unfortunate recipient of one of these and the TV was only a few years old itself, meaning these capacitors are still around. Problem was, the cap discharged and took a few other things with it on the way out.

No idea if that is any help to you or not, but may be worth taking a look at the rest of the components whilst your at it...
 
That resistor is getting hot from something. Whether its something else on the board or it has a fault I can't say. Measuring in place you will be measuring the resistance of any parallel path as well so unless you know there is nothing in parallel, you need to remove the resistor to read its value. Resistors usually go open though so they don't heat up when they fail. Heating is usually a sign that something else has gone short and is pulling too much current which heats the resistor. Its usually a transistor somewhere.

The capacitor plague affected electrolytics. I can't see any of those on that photo but there could be others hiding round the corner somewhere.

Cheers
Dave
 
since that one has a couple twins, I wonder if that isn't part of a rectifier circuit and you got nailed by lightning. Swap the resistor. measure the old one out off the board. It should read 100 ohms normally, hopefully its bad. When you put the new one in measure voltage across all of those resistors. They should read about the same.
 

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