# Identify this failed electronic component for me **URL:** \ **Category:** Factual Questions\ **Created:** [February 10, 2021, 11:55am UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601 "2021-02-10T11:55:13Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![TokenRing](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokenring/32/3559_2.png) [@TokenRing](https://boards.straightdope.com/u/TokenRing)\ **Post date:** [February 10, 2021, 11:55am UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/1 "2021-02-10T11:55:13Z")
I have a failed network switch (Netgear4 port POE FWIW) that I fancy attempting to repair. I’ve gone to the trouble of disassembling the miscreant device and have located a component on the board with signs of catastrophic failure - charred or burnt circuit board at one end. The component is labelled as “FB2” on the circuit board and is a grey cylinder. > **[switch.jpg](https://drive.google.com/file/d/1ZbVxyoqe0FqgpU8sgywFl48ojRmk72Jn/view?usp=sharing)** > > Google Drive file. With luck the link will take you to a picture of the board Question: What would I need to order to attempt a replacement? ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [February 10, 2021, 12:09pm UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/2 "2021-02-10T12:09:53Z")
FB2 looks like a diode but I doubt that is the cause of the malfunction. Most likely, It is one of those electrolytic capacitors that have gone bad. ---
**Author:** ![TokenRing](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokenring/32/3559_2.png) [@TokenRing](https://boards.straightdope.com/u/TokenRing)\ **Post date:** [February 10, 2021, 12:45pm UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/3 "2021-02-10T12:45:26Z")
ah. I hoped it was the grey thing as it looks to me broken. I don’t think it is a diode as there doesn’t appear to have any polarity indicators on it. I’ll look more closely at the capacitors to see if there are any indications of failure. Thanks! ---
**Author:** ![pjd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pjd/32/3009_2.png) [@pjd](https://boards.straightdope.com/u/pjd)\ **Post date:** [February 10, 2021, 1:31pm UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/4 "2021-02-10T13:31:46Z")
FB usually stands for [ferrite bead.](https://en.wikipedia.org/wiki/Ferrite_bead) > [@TokenRing](#): > > The component is labelled as “FB2” on the circuit board Did you mean FB1 ? That one looks a bit burnt . ---
**Author:** ![TokenRing](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokenring/32/3559_2.png) [@TokenRing](https://boards.straightdope.com/u/TokenRing)\ **Post date:** [February 10, 2021, 1:35pm UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/5 "2021-02-10T13:35:38Z")
yes I did mean FB1. Ferrite bead eh? Thanks! ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [February 10, 2021, 1:50pm UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/6 "2021-02-10T13:50:23Z")
FB is usually a Ferrite Bead. They are usually used for noise suppression. ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [February 10, 2021, 1:57pm UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/7 "2021-02-10T13:57:12Z")
Is the cost of replacing the switch so prohibitive that you feel the need to repair it instead? I ask because there is a reason that happened in the first place, and there may be more damage that you can’t see. ---
**Author:** ![TokenRing](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokenring/32/3559_2.png) [@TokenRing](https://boards.straightdope.com/u/TokenRing)\ **Post date:** [February 10, 2021, 2:03pm UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/8 "2021-02-10T14:03:43Z")
I’ve replaced it already. Just fancy seeing if I can repair the failed one. ---
**Author:** ![jjakucyk](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@jjakucyk](https://boards.straightdope.com/u/jjakucyk)\ **Post date:** [February 10, 2021, 2:23pm UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/9 "2021-02-10T14:23:41Z")
Looks like there could be some damage to the circuit board leading to C3. Either that or it’s just dried/crystallized chemical that leaked out of FB1. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [February 10, 2021, 2:27pm UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/10 "2021-02-10T14:27:06Z")
Just about to point that out. Not sure what is on the board there by C3, might be fluid that leaked out of another cap. Between my eyes and the resolution can’t tell if it’s anything. ---
**Author:** ![TokenRing](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokenring/32/3559_2.png) [@TokenRing](https://boards.straightdope.com/u/TokenRing)\ **Post date:** [February 10, 2021, 2:50pm UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/11 "2021-02-10T14:50:44Z")
Another angle to further waste your time > **[switch2.jpg](https://drive.google.com/file/d/1ZfcUuQn-QMzzV2WEiVkBHs7l3MbYw9a3/view?usp=sharing)** > > Google Drive file. Seems there is some damage to the base of the larger capacitor. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [February 10, 2021, 2:57pm UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/12 "2021-02-10T14:57:22Z")
Electrolytic capacitor leakage. No easy way to be sure where the corrosion has got to. In my limited hobbyist experience, this is the point where I start salvaging usable components from the non-damaged portions of the PCB and dispose of the rest. ---
**Author:** ![TokenRing](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokenring/32/3559_2.png) [@TokenRing](https://boards.straightdope.com/u/TokenRing)\ **Post date:** [February 10, 2021, 3:21pm UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/13 "2021-02-10T15:21:34Z")
Thanks @gnoitall and everyone else too. Seems likely I’ll give up on my ill-thought-out plan to repair this widget. Yes, you’re right, I am a congenital quitter. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [February 10, 2021, 3:42pm UTC](https://boards.straightdope.com/t/identify-this-failed-electronic-component-for-me/932601/14 "2021-02-10T15:42:08Z")
It would be an interesting experiment, something to help build your knowledge of electronics, but very likely produce no other useful results. So maybe not worth any more effort, but no one would blame you for removing the likely affected components, re-evaluating your decision, then still deciding it wasn’t worth the effort, yet still tossing the board in with the others you’ve collected in the same manner and in less time than you think pulling it out and marveling how the modern electronics in just a few years have reduced that switch to something the size of a Tic-Tac.