Microinverter repair - mystery component identification - Page 1
Forum section: electronics / repair

author: Trailing Edge
author_rank: Contributor
timestamp: September 29, 2024, 02:05:19 pm
content: Can you help identify this part?It's the "cap" on top of a small component that has turned its interior into magic smoke and departed from its base. I can read it, but the text on it seem to be misleading me.EDIT: (this attachment didn't go through)It came from here, at F1. You can see the circular base of the component still soldered to the board, with nothing left attached to the leads.This the picture of the whole board. I've removed only the encapsulation around this part.The board is inside a PV microinverter which has 4 panel connectors (bottom). It is an Altenergy Power Systems QS1 microinverter. I'd like to rescue it and keep it as a spare/backup for when the next one fails.Thanks for looking!

author: Trailing Edge
author_rank: Contributor
timestamp: September 29, 2024, 02:07:45 pm
content: The missing image:Ahh, Simple machines forums... not so simple sometimes.

author: Jimmy Electron
author_rank: Contributor
timestamp: September 29, 2024, 02:11:03 pm
content: Hi there.It's a 10A DIP mounted radial cylinder fuse

author: Trailing Edge
author_rank: Contributor
timestamp: September 29, 2024, 02:51:32 pm
content: Bingo!The specs looked like fuse specs, but I couldn't figure out what kind.Thank you!

author: fzabkar
author_rank: Super Contributor
timestamp: September 29, 2024, 06:10:17 pm
content: T10A is a time-lag fuse.https://www.schurter.com/en/datasheet/typ_MXT_250.pdf

author: Trailing Edge
author_rank: Contributor
timestamp: September 29, 2024, 06:39:06 pm
content: Found the part on Digikey, I'm good to go.Thanks again!

author: Trailing Edge
author_rank: Contributor
timestamp: September 29, 2024, 06:47:54 pm
content: WaitWhy is this component in this device? A fuse like this blows once on a fault and isn't "replaceable". Yes, I can jury-rig it, but not easily. It has to be excavated out of the encapsulation to get at the leads. And if I wanted to fully replace it with pristine solder joints, I'd have to remove the entire board from the cast-aluminum case (more encapsulation gunk to remove). All just to replace a fuse.I agree that the unit has to be sealed and IP67 forever but what's the harm in a little fuseholder sitting high and dry above the pool of encapsulation polymer, within the enclosure? Pick-n-place a different component and it hardly makes the board more expensive, would it?This device is designed to be thrown away if there's ever an external fault or if it's hooked up wrong. The manufacturer has lost sight of why their customers want their products - less wasteful consumption (speaking of materials or energy, most people would say both). What a waste.

author: Jimmy Electron
author_rank: Contributor
timestamp: September 29, 2024, 07:44:12 pm
content: It's an unfortunate fact of our modern world that much of the consumer electronics is not intended to be repaired by anyone other than 'authorised' techs.IMO this is just a racket to squeeze every last cent out of us but hey!

author: Haenk
author_rank: Super Contributor
timestamp: September 30, 2024, 04:48:02 am
content: The gunk ist the last barrier against moisture, in case the outer seal breaks. Unfortunately this makes these outdoor devices pretty unrepairable.

author: Jeroen3
author_rank: Super Contributor
timestamp: September 30, 2024, 07:06:32 am
content: Fuses are to prevent fires. There is something else wrong with the unit.

author: Xena E
author_rank: Frequent Contributor
timestamp: September 30, 2024, 09:29:25 am
content: Quote from: Jeroen3 on September 30, 2024, 07:06:32 amYes, fuses don't 'go wrong', there is a reason it blew, replacing it will just create an incendiary of the next fuse perhaps not immediately, but it will.Investigate the cause first.

author: Trailing Edge
author_rank: Contributor
timestamp: October 01, 2024, 03:49:19 am
content: Indeed.After I replace the fuse, I'll have to be watching for fault currents while I start it up.Unfortunately the encapsulation makes "snooping" pretty difficult without extensive excavation and dismantling - all likely to do more harm than good.This microinverter is already scrap, and I am trying to fix it just so that I can have a working spare on hand. For when the next inverter fails. Which is inevitable, it seems.If my tinkering fails, not a big loss. I just have to proceed carefully.

author: Trailing Edge
author_rank: Contributor
timestamp: October 13, 2024, 10:33:53 pm
content: Looks like Jeroen3 and Xena are right.Something else is wrong with this unit.I replaced the fuse, but when I attempted to power it up, it gave no sign of life.I'll keep searching for another problem.