I'm trying to fix a 5 years old dishwasher board that burned. One electrolytic capacitor dried out so I'm replacing all of them on the board (5) but there's also a resistor which I think is a high power resistor that I would need to replace. How can I know what value it was since it burned?

 

Is it open? Put an Ohmmeter between the ends.

I am guessing that it will be low Ohms, (<100). It looks to be a 1W power resistor.

 

I removed the resistor from the board and the Ohmmeter shows 42K. Is it reliable even though the resistor burned?

 

I removed the resistor from the board and the Ohmmeter shows 42K. Is it reliable even though the resistor burned?

Not likely. The first color band appears to be brown, so it would be either a 0.1xxΩ, 1.xxΩ, 1x.xΩ, or maybe 1xx.xΩ

You will have to get a schematic from the maker, or trace out the power supply section.

Begs the question, what caused it to overheat in the first place? The resistor is there to limit current; something elsewhere is drawing too much current; that smoked the resistor. You will have to also find the root cause;not just replace a resistor...

 

I was able to find a picture of the electronic board. The resistor is located on the bottom right (R189). I think the bands are orange - brown - black (31ohm), what do you think?

 

No! Note the slot in the board under R189 and V1. This is usually done when there is a high voltage between two tracks or that extra safety isolation is required.

What I would do is to try and trace out the circuit in this area by following the tracks and find out what this component actually does. Looking at your photo it looks like this resistor is in series with C177. Is this capacitor good. Might have gone short-circuit. But there might be more tracks that we can't see. So check carefully. Report back when you know more.

 

My colour vision is poor, but I reckon the left-most band is red and the right-most is gold.

 

Looks like Brn-Brn-Blk to me (11Ω) ...

 

This is usually done when there is a high voltage between two tracks or that extra safety isolation is required.

Well spotted.

As a result make sure there are no sharp bits when you resolder the new one in and keep it slightly raised off the board.

Yes I agree from mike's photo, 11 ohms.

 

11 ohm is not a typical value, so my guess would be brown-red-black that gives a standard 12 ohms. Or it could be red-red-black that gives 22 ohms.

 

If you look at the original picture of the burned resistor, I think the first band looks more red than brown.

 

11 ohm is not a typical value, so my guess would be brown-red-black that gives a standard 12 ohms. Or it could be red-red-black that gives 22 ohms.

Dobri Den,

Since the last band in the OP's photo is gold, then 11Ω is a standard value in the 5% line up.

 

Hello,

It could be red-red black, wich is 22 Ohms, a standard value.

Bertus

 

I'd remove it from the board and take a look at the other side. It might not have gotten quite as hot.

It looks more red to me than brown.