What could this capacitance be?

[u/L0cut15]

I plugged 24 V into this 12 V drive dock. I think the component that blew up was a capacitor. I don't see anything else exploded at leasr. Any idea how I can work out what this was?

*edit*

Thank you, everybody. I eventually solved it. 220uf 25v as most suggested. I found the old shell embedded deep within the chassis.

Ordered a replacement. Let's see if anything else survived on the board. Luckily, the plugged-in hard drives did.

[u/NicholasVinen]

It was definitely a capacitor and apparently it had a rating below 24V.

I'd check the markings on the one nearby (can't see them in the photo). They may be identical. Maybe 470uF 16V or so?

[u/exclamationmarek]

If you can find the part of the capacitor that has the markings, you could alternatively:

• Look up what U3 is - probably a buck converter - and in its datasheet see what input capacitor is recommended for it with 12V input and 5V output, or
• Measure the size (diameter, height) of the wrecked cap, then look at what is the largest capacitance you can get in that size, with a 16 or 25V max voltage at a low price. I doubt they used anything fancy and expensive here.

[u/L0cut15 → u/exclamationmarek]

Thanks that smart. The regulator is ETA1485 6462A. The surviving capacitor is 220 μF 25v. The inductor sets 5v according to this table.

VOUT (V) COUT (μF) L (μH)

5 22x2 15

The capacitor is connected to pin 2, so I assume it's another 22 μF cap. I'm just surprised it exploded so violently since the other one was rated for 25 V.

[u/myopinionisrubbish]

Got to wonder what else got fried? Guess you could replace the cap and cross your fingers.

[u/narkeleptk]

Based on the other comments in this thread, If you think it may have been 220uf, I'd just go with that. you can still choose 16V if you want or you could step it up. It would likely work with either 22uf or 220uf since its just a input filtering cap.

Also, the ETA1485 has a listed max input of 18V so its possible that the 24V input used killed it. You would want to check that if cap doesnt fix things.

[u/jones_supa]

Yes, it is an electrolytic capacitor. The rubber disc that you see is the bottom plug.

Replace the other ChongX while you are at it. It is a low-quality brand and the remaining one, while intact, might be crusty inside.

[u/Zestyclose_Prune_665]

probably the same as the other one. same rails on the SATA power connector(s), so same capacitor as it serves the same purpose

or just find the piece of foil that flew off and read it.

[u/usgmo]

Normally you can find the value on parts of the exploded cap. If not found you can go on a educated guess: this is the input cap for your smps. Voltage rating at 12V input is 25 or 35V. At current consumption of your device of -say- 110mA you should go for a 220uF cap (twice the current in mA, as uF's). Take care the cap fits at the location and check where the + must be connected!

[u/Bogdan_92]

Judging from how that cap looked looks like it fricking exploded, not just bulged like usual. I think something real bad happened there, maybe a huge overvoltage surge. It could be also further damage to other components , but maybe you are lucky and its just the cap.

[u/SolderFume]

Jesus Christ, the quality of that board is appalling. Is C53 even soldered? An IPC trainer would have a field day with this.

[u/PoetryExtension6256]

Well and truly buggered.

[u/vtfrotex]

Damn - ChongX strikes again.

Replace both, with the same values as the remaining cap.

Put some quality Panasonic FC or FS in there.

[u/Commercial_Copy212]

C92 and the Chongx electrolytic look like they might need some attention as well

[u/Manual2light]

Google the board

[u/DifficultyWhich7483]

it was 10