0
\$\begingroup\$

tl;dr: how to procure a SMD replacement if all i know is the 3R3 marking and sizes (square 6.5mm sides, 2.9mm tall), with no extra information on thermal, etc.

One component on my motherboard fried to the point i can barely read the top markings. It's a large SMD one with only two large pads, so i believe I can replace it with a hand soldering iron.

I have zero experience with SMD stuff and can't really ID it. Looks like a resistor from the rest of the circuitry. 3R3 = 3.3Ω? That is a stock photo and shows top markings 3R3 348 CXD, On my same revision board, both of those are labeled 3R3 518 R06 so I am guessing the last 6 digits are just factory/serial garbage.

That region of the motherboard is clearly the power regulator from the 12-19V input plug. So i guess don't have to worry too much about anything else other than correct resistence value and Thermal capacity i guess, right?

AM1h-ITX motherboard with burned component marked in green

\$\endgroup\$
4
  • 3
    \$\begingroup\$ Given that it is in the middle of a switching powersupply, it might well be an inductor rather than a resistor. \$\endgroup\$
    – JRE
    Commented Jul 16, 2020 at 20:41
  • 3
    \$\begingroup\$ It is most likely an SMD inductor from the looks of its package. \$\endgroup\$
    – Jakob Halskov
    Commented Jul 16, 2020 at 20:42
  • 2
    \$\begingroup\$ Keep in mind that it's unlikely to be the only part that is "fried". \$\endgroup\$
    – Spehro 'speff' Pefhany
    Commented Jul 16, 2020 at 20:53
  • \$\begingroup\$ @SpehroPefhany i know, but there's no option to buy a new one today. We live in an age that the factory-included CRC battery outlast the life of the product. Going to give it a try before replacing CPU for lack of board options. \$\endgroup\$
    – gcb
    Commented Jul 16, 2020 at 21:48

1 Answer 1

Reset to default
3
\$\begingroup\$

It is most likely an 3.3uH SMD inductor. Something like the one shown here: https://www.sunrom.com/p/33uh-3r3-10a-smd-aspi-0630lr-3r3-inductor

It is indeed easy to get confused and believe this is a resistor when the marking includes the “R”.

\$\endgroup\$
2
  • \$\begingroup\$ Thanks. I see the same 3R3 marking used from components with a wide range of other attributes besides 3.3uH. I know i need shileding just from the looks. but there's also max i from 1A to 30A, and DC r from kΩ to 10s of MΩ. Any way to figure those out from the original markings? \$\endgroup\$
    – gcb
    Commented Jul 16, 2020 at 21:43
  • 1
    \$\begingroup\$ guessing this is a good replacement based on the ranges of the nearby components: mouser.com/ProductDetail/673-PA5005.332NLT \$\endgroup\$
    – gcb
    Commented Jul 16, 2020 at 22:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.