Identifiying SMD component - Page 1
Forum section: electronics / beginners

author: New Nubby
author_rank: Contributor
timestamp: September 08, 2022, 02:10:25 am
content: Hey Guys new to EEVBlog forum. But i have a ifi hip dac, a battery powered amplifier. I was charging it the other day, but i plugged it into my overseas mobile charger. And the AU adapter if moved via the cable can spark ( need a better adapter ). But i was hesitant and plugged it into the portable AMP. I may have plugged the USB-C laptop power but more likely the overseas mobile charger. Either way i left it. And when i came back. The Amp would not turn on nothing- zip.So i took out the four screws and using macro mode, i found out a SMD component blew. As can be seen by the pictures. The SMD components around it that look similar no markings. Apart from the one that blew. So even if it didn't blow, or wasnt as bad. I doubt i would of been able to find out what the spec was aside it saying R200. I am a new Nub to the electronic world so not sure what the r200 represents...Any and all help appreciated. Have more pics if need it. If want to know more don't hesitate to ask.I want to know what the electronic SMD part was that blew?As not other sign on amp has anything blown or burnt, aside that one SMD, with some scorching on the SMD Capacitor near it

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 08, 2022, 02:16:39 am
content: blown D200 is probably a diode the same as D201-203 brotherhood. in what orientation that depends on what the circuit is doing. and why its blown? that needs further investigation. if you install new, that maybe blown again ymmv. whats the IC near R200?

author: New Nubby
author_rank: Contributor
timestamp: September 08, 2022, 02:23:04 am
content: Just uploaded more pics if helps to see what the IC near r200 is.You mention same as D201-203 brotherhood. What are the numbers representing. I thought the number just reflects the electronic part ?

author: tooki
author_rank: Super Contributor
timestamp: September 08, 2022, 06:53:06 pm
content: It's just an identifier. Mechatrommer means that there's a decent chance the same model of diode has been used for all of them.

author: gamalot
author_rank: Super Contributor
timestamp: September 08, 2022, 07:57:07 pm
content: U200 is RT9481https://www.datasheets.com/en/part-details/rt9481gqw-richtek-technology-corporation-76420678Traces connected to D200 are wide, I guess it should be a Schottky diode, the other diodes (D201-203) are 1N4148.

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 08, 2022, 10:19:20 pm
content: Quote from: gamalot on September 08, 2022, 07:57:07 pmif you are right (still not clear from pictures), and i'm reading the datasheet and the dot correctly, the diode (probably just a reverse protection schottky) is feeding VBUS pin. if replacing the diode result in another blow out, that IC is suspect or anything its feeding power to, a battery? or anything else. D200 is visually the same size as D201-203.. if by chance the D200 is underrated during design stage, replacing with bigger schottky may fix it, but then it also can make it worse, ymmv.

author: New Nubby
author_rank: Contributor
timestamp: September 10, 2022, 12:27:52 am
content: Since you guys mentioned not to clear from the pictures. Thought to do a quick macro video on the board and site/diodes in question.https://youtu.be/cfqcZIE5HfYSo you guys get a better look and have a more detailed pic/video of the board. The auto zoom was playing up. Pardon the shite video, but in Dolby atmos ( jk ). Also if i can get away with the same diode as the D201 ( it might blow as you mention due to something else going wrong or other IC.https://ifi-audio.com/products/hip-dac/= Some good news too, the product page has a low quality picture of the circuit board, so seeing that unblown diode, hoping that helps. =https://ifi-audio.com/wp-content/uploads/2019/10/hip-dac-board-1-copy.jpgIf the surge or causing fluctuations maybe from the voltage/current did it from using a sparking overseas charger with crap AU adapter. Or if i used the laptops type-C charger. Though i use the laptop 65W charger on my mobiles as it detects what current/voltage it needs from what i have observed. But if the ifi DAC amp from the moving the cable ( it sparks when it does ).But in case it was the overseas mobile charger with loose connection. Or perhaps the laptop charger caused the diode to blow. I mean might be something else and might get another blown diode. But maybe the ifi Dac amp is more sensitive and not as protected as the mobile due to internal circuitry ( yes threw the overseas charger away lol ). But worth saying the 350 portable amp. Again all thoughts welcome and all help has been appreciated as i was hesitant using faulty sparking charger ( never again )

author: gamalot
author_rank: Super Contributor
timestamp: September 10, 2022, 06:23:39 am
content: I found a high-res picture and it looks like the D200 is a 1N4148, although the traces connected to it are wider.Also I found pictures of the next generation iFi hip-dac2, the D200 was moved to the bottom side of the PCB, but it can be seen that it is a 1N4148.

author: New Nubby
author_rank: Contributor
timestamp: September 11, 2022, 01:17:16 am
content: Now that is a Super epic find. How did you find higher res version of the board ? Thank you for the effort very cool of you.Since now we know the diode, where can you just buy one that is the same ie SMD surface mount rather then the through whole types ( yes i can technically solder surface mount ones there. But will that make a diff from the SMD sort? As when i look it up they are mostly(hermetically sealed) Axial Leaded Through-Hole.

author: gamalot
author_rank: Super Contributor
timestamp: September 11, 2022, 02:51:20 am
content: Quote from: New Nubby on September 11, 2022, 01:17:16 amYou can buy surface mount 1N4148 online, element14 is trustworthy but they charge $15 for shipping if your order is less than $50, of course you can choose eBay to save money.

author: New Nubby
author_rank: Contributor
timestamp: September 11, 2022, 03:12:06 am
content: What do you think as $15 isn't much knowing the device is 350. Unless it pops again then arggfor shipping price. I saw this Axial Leaded Through-Hole at jaycarhttps://www.jaycar.com.au/1n4148-1n914-signal-diode-pk-5/p/ZR1100.But not sure the quality or if the exact one. Also does it make a difference if you get through hole or surface mount ?And what's the link to the Surface mount at element14 just seeing the through hole. For some reason have trouble finding 1N4148 SMD surface mount ones, most through hole. So any thing you find be good or should i put WS at the end or any other acronym for surface mount version ?Again much appreicated. As i will once i get one solder and remove the battery for sure before. Should i test if the D201 to D203 have reverse voltage going through or they would due to the battery still letting electricity through

author: gamalot
author_rank: Super Contributor
timestamp: September 11, 2022, 04:40:56 am
content: Quote from: New Nubby on September 11, 2022, 03:12:06 amFor your case, I think the difference in electrical parameters between surface mount or through hole devices is not that important, what you need to care more about is the difference between their dimensions. I took a picture that might help make it easier for you to decide which one to use.The links I found for eBay and element14 are here:https://au.element14.com/on-semiconductor/1n4148ws/diode-small-signal-75v-sod-323f/dp/2453269?st=1n4148https://www.ebay.com.au/itm/363329195000

author: New Nubby
author_rank: Contributor
timestamp: September 16, 2022, 09:28:50 am
content: Again appreciate the help. I will go with ebay, in case it blows suggesting its an IC or something else. If it works. Then possibly the arching spark or surge possibly from using a cheap and nasty au adapter ( every-time you move the cable attached you hear it. Especially if the device doesn't have decent protection i supposed, as my mobile had to endure it for a bit. Yes getting a 33w charger lol.) Au adapter for my international mobile charger. Or if i used the USB-C laptop charger. But always use the usb-c laptop charger for other devices, as it can detects voltage and current and does output more. Used a meter to test this. So more likely moving it attaching to sparking adapter. OR something elseIf it doesn't blow i think worthwhile get a decent quality one from element. As the device is $350 so not to expensive for that part that might be $20 or more with postage. Will post results and pictures when i get the part