Need help! One more LTC3780 Fried!!!

[chiken]

Hello, so i bought this little "thing" from ebay, because i needed regulative psu, for leds and some batteries... but what happened is that i hooked it up
and it worked for maybe 20 seconds and i heard nice sparkling and had some fireworks    , and i removed heatsink and found that 2 mosfets are bad, one got shorted and fried another one
(RU3060L, i cant find them to buy, so if you could tell me where to buy would be also helpful), so does anyone what happened and what should i do now?
Should i request ebay refund, because im sure i did not do anything wrong, connected to 20V battery, NO I DID NOT shorted output because i used VOLTMETER, and i DID NOT connecteed input backwards...

seller said that he would send me another one(which i highly doubt because hardly any seller sends another one, just waits for it to get too old for any compliants)
i mean it wasnt too expensive but 15$ is not cheap for me as a student...
what do you guys suggest?

[Cliff Matthews]

Normally advice is given and taken quite freely, but you have not given enough to allow anyone to help! You need to consider posting a picture, schematic, connection diagram or even a link to what this little "thing" is.. I suspect it's a Chinese module? If so, post a link from where you bought it.. at least we can see the product to get an idea.

There's always a reason fro not getting a reply, but Welcome to the forum!

[chiken]

Wow, damn i was entirely sure i linked picture of it but it looks like i did not 
Anyway it says like this : ( LTC3780 Automatic Lifting Pressure Constant Voltage Step Up Step Down 10A 130W )..
Voltage can be adjusted from 0.8 - 30Volts, and current limited to 150-10AMps...

I dont know how to upload image so heres a link https://imgur.com/a/PMY2kHU

[Cyril.Anthony]

You can buy the mosfets here
http://Https://lcsc.com/product-detail/MOSFET_Shenzhen-ruichips-Semicon-RU3060L_C107709.html

What is the rating of the LEDs and how many you were trying to drive?

Sent from my SM-G950U using Tapatalk

[chiken]

One, 10watt one, it worked (used it 5 seconds because led doenst have heatsink so it would overheat if i used it more) but board died when nothing was connected to it, after 5 secs of led i disconnected it and took my voltmeter and connected it, then i rotatet potentiometer a little bit to see how stabvle and precise it is, and then siply started sparkling... around 25volts...

oh boy, mosfets are 0.5$ and shipping would be 10$, it will have to wait until i order something more so it would be worth it

[chiken]

I see that nobody has any clue about this ( chineseum made so no wonder why  )
I saw another post with identical issue, and that guy replaced mosfets but board still did not work properly so i think that i should get another one..
so now main question is should i ask for a refund?
because it came "in working order", but as soon as i hooked it up it got fried... so mosfet surely was bad before i recieved it...
Im pretty sure that seller wont give refund, but will insist to "send me another one" which he will never do it, but waste my time so 30days of money back guarantee passes...
So what do you thing about it?

[mvs]

One, 10watt one, it worked (used it 5 seconds because led doenst have heatsink so it would overheat if i used it more) but board died when nothing was connected to it, after 5 secs of led i disconnected it and took my voltmeter and connected it, then i rotatet potentiometer a little bit to see how stabvle and precise it is, and then siply started sparkling... around 25volts...

oh boy, mosfets are 0.5$ and shipping would be 10$, it will have to wait until i order something more so it would be worth it

30V MOSFETs are not suited for the task, look for something better then RU3060L.
AOD4186 from your board picture is a better choise.

[Cliff Matthews]

Cheap too. https://www.ebay.com/itm/5pcs-AOD4186-D4186-N-Channel-Enhancement-Mode-Field-Effect-Transistor-TO-252-/253227047830

[chiken]

Thank you, i ordered them
But what you thing about refund?