this post was submitted on 04 Jul 2023
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Mates bread maker stopped working so I had a look inside and saw this burned resistor.

I'm guessing the heat changed the colors a bit so wondering if anyone has experience in reading cooked resistor values.

I removed it from the PCB and measured it at 403 Ohms.

Thanks for any help.

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[–] [email protected] 17 points 1 year ago (12 children)

It looks like 1GΩ (black-brown-white gold). But that doesn't sound likely unless you have a very high voltage bread maker.

If we treat the black band as discolored-brown, and read it the other way, we get (yellow - white - brown - brown) which is 490Ω and closer to your measured value. I wouldn't rule out (yellow - white red - brown) either at 4.9 kΩ, although that doesn't match closely to your measurement.

A good question is 'why did the resistor burn?'. If I didn't know why, then I would assume that replacing it will just result in it burning again, although maybe not immediately.

[–] [email protected] 6 points 1 year ago (2 children)

Thanks! I'll try replacing it with a 490 ohm resistor and see if it works again.

The element in the bread maker looks like it came loose a bit and made slight contact with the internal metal housing. I wonder if that caused the resistive element to sink more current than the PCB was designed for, burning out the resistor.

[–] [email protected] 4 points 1 year ago

That sounds like a possible fail state. Also shitty design. It should use a resettable thermal fuse or something to detect faults without parts burning.

Consider maybe adding a fuse to the design?

[–] [email protected] 1 points 1 year ago

You'll need a fairly high wattage resistor. That one looks like maybe 1W but it might be more.

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