A baffling little resistor... what value?

Thread Starter

MarkZank

Joined Apr 14, 2021
4
Greetings to eveyone! I am looking for help on a burnt resistor I am trying to replace on a board (see attached).
Initially I just thought it was an easy matter, a red-red-orange-orange-silver = 223kohms 10% tolerance (so, I could use a common 220kohms with 5%, given 223kohms resistors seem to be so hard to find...). But then in a repair kit for the board I found this munchy labeled as a 0.22 ohm (?!)
Just a typo or am I missing something? For reference (and to help people later googling for this same component), this is part R9700 in a DPS-162KPA-1 power supply board.
Thanks so much for your help!
Markbaffling-resistor.jpg
 

Thread Starter

MarkZank

Joined Apr 14, 2021
4
Great info thanks, so the final calculation would be 22 * 0.1 * 0.1 = 0.22ohm (= repair kit info was right!), with gold both in 3rd and 4th? I was baffled because seeing the same color both in 3rd and 4th on a 5-band I assumed it could just not be gold... the same diagram above gives gold only in 3rd. That's kind of weird as I couldn't see anywhere mentioned a possible gold-gold combo in 3 and 4 (!) :-[]
 

Thread Starter

MarkZank

Joined Apr 14, 2021
4
So the winning solution to the baffling enigma, on this 5-band, would be: 22 * 0.1 (gold) = 2.2ohm + gold (5% tolerance) + gray-and-not-silver (1ppm/k dammit temperature coefficient)?
If so, repair kit information wrong by a 10 factor and my first guess wrong only by 10^5 (very cold shower needed)? :)
 

ApacheKid

Joined Jan 12, 2015
418
So the winning solution to the baffling enigma, on this 5-band, would be: 22 * 0.1 (gold) = 2.2ohm + gold (5% tolerance) + gray-and-not-silver (1ppm/k dammit temperature coefficient)?
If so, repair kit information wrong by a 10 factor and my first guess wrong only by 10^5 (very cold shower needed)? :)
Assuming its not an inductor!
 

Ian0

Joined Aug 7, 2020
3,186
That textured coating is generally used on flameproof resistors, and indeed it appears to have failed without catching fire!
Is it on the mains input of a small switched-mode power supply, by any chance?
 

Thread Starter

MarkZank

Joined Apr 14, 2021
4
Thanks to everyone for solving the mystery, you saved me from a silly mistake! :)
@Delta prime: four or five, 2.2 Ohm it is so all is well!
@ApacheKid: yes, I bet an inductor would have done less damage than putting a 223k...!
@Ian0: it's on the primary in a power supply board of a large tv (DPS-162KP-1 on a Sharp Acquos), see pictures.
Actually that was not the only faulty part, another Schottky diode also failed, but that only had one band not five...! ;-)
Now I have soon to get that cold shower, with a deep meditation chant called "223k vs 2.2" (an om for the ohm!)
 

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