Identification of a resistor-looking element

Thread Starter

gromas

Joined Feb 4, 2024
4
Hi! I have a problem. I'm trying to repair something and theres a burnt resistor looking thing, but the resistance of it would be 28 Ohms, and theres no resistor on the market like that. I'il attach a photo of it and maybe you can help me identify it.IMG_0022.JPEGIMG_0024.JPEG
 

panic mode

Joined Oct 10, 2011
2,753
more common value is 27 Ohm but any electronic supplier will also have bunch of resistors with value of 28 Ohm. DigiKey shows literally hundreds of them:
https://www.digikey.ca/en/products/...LwJ5sMBIN7UAHmIkBfeexhQA2iGa0CtDAHtGAAhABdeUA

but the original value may as well be something else, after all the component is damaged.
to me it looks like resistor but if it is not a resistor, maybe it is an inductor... maybe.
i would look for any ICs near it and try to find the datasheet.
 

sagor

Joined Mar 10, 2019
912
The board has a label "RF1" next to the hole. That suggests an inductor. But, who knows how well those board labels are made, and whether they use a resistor for "RF1". They might mean "Resistor F1"
 

Ya’akov

Joined Jan 27, 2019
9,170
Welcome to AAC.

From the designation on the PCB (RF 1), and from its appearance, and condition—that is a fusible resistor. It is a common component but the color code is badly damaged and I can't really read it.
 

Sensacell

Joined Jun 19, 2012
3,452
Thanks Y'all, ig i'il try to buy a fusible resistor and a inductor and see if it works
The chances that replacing this part will fix the device are almost zero.

Fusible resistors are there to open the circuit and prevent fires when other parts of the circuit fail and draw large currents.
Other parts are also toast, these switching power supplies are not simple to fix.
 

Thread Starter

gromas

Joined Feb 4, 2024
4
The chances that replacing this part will fix the device are almost zero.

Fusible resistors are there to open the circuit and prevent fires when other parts of the circuit fail and draw large currents.
Other parts are also toast, these switching power supplies are not simple to fix.
(i might be wrong, and probably am) idk if its a switching supply. I’d say its a capacitive one cuz theres lots of capacitors and theres only 1 ic on the whole board that doesent seem like a switching converter
 

MrChips

Joined Oct 2, 2009
30,821
Tell us what is the product or device (make and model) where the board was used.
Post a picture of the whole board.
 

Thread Starter

gromas

Joined Feb 4, 2024
4
It’s the silvercrest slr 30 a1,I’il put in photos of the board and a burnt (?) piece that I found also IMG_0030.jpegIMG_0028.jpegIMG_0026.jpegIMG_0027.jpegIMG_0029.jpeg
 

HasBeen

Joined Jul 28, 2023
29
The photo with the turns of wire showing make me think it is an inductor, not a fusing element. However, if enough current flows through it, it will "fuse" and end up looking like that. If I'm right, you need to look for the cause of the excess current through the component before you simply replace it with another.
 

Ian0

Joined Aug 7, 2020
9,835
Definitely a fusible resistor. There would not be a small inductor in that position, because there is already a large inductor in that part of the circuit (LV1) as well as a common mode choke.
And it won't work again until that dead IC has been replaced!
 
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