Skip to content
WhatSMDSign in

SMD code 77D

Marking codes are not standardised, and the same code is reused by unrelated makers for unrelated parts. Below is every part in our tables printed with it, and any printed with a code that is easy to misread as it, from the manufacturers' own marking tables and published code lists.

77D on a chip resistor

619 kΩ

619 kΩ resistor, 1%

EIA-96 precision code: 77 selects 6.19 from the E96 series and D multiplies by 100000. These are 1% parts.

Check it with a meter

Lift one end and measure across it. A good one reads 619 kΩ within 1%. Measuring it in circuit reads the parallel combination of everything around it, which is almost always lower, never higher: well above 619 kΩ on the board is a fault. Open, or well above 619 kΩ, means it has failed: burnt, cracked or corroded. That does not change what to fit: the marking still says 619 kΩ. A burnt resistor usually means the part it feeds drew too much, so find that before fitting a new one.

On a transistor or diode body (SOT-23-5, SOT-23, DFN), 77D is a part code instead. Those parts are listed below.

3 parts are printed 77D

Not sure which one you have?

Answer up to 4 quick questions and these 3 parts are ranked, with a meter test that settles it. It works on a dead part too.

  • SD0771D3WSOD-323ESD protection diode, 2 pins, LeiditechESD protection diodeSOD-3232 pinsLeiditech
    What it is
    ESD protection diode
    Maker
    Leiditech
    Package
    SOD-323
    Pins
    2
    Details
    ESD protection diode, VRWM 7 V, Cj 550 pF
    Source
    Manufacturer datasheet

    Is it dead? The meter test is below: TVS or ESD protection diode.

    Datasheetfor SD0771D3W, opens in a new tab
  • KIA7725SSOT-23Voltage supervisor, 3 pins, KECVoltage supervisorSOT-233 pinsKEC
    What it is
    Voltage supervisor
    Maker
    KEC
    Package
    SOT-23
    Pins
    3
    Details
    Voltage detector IC: 2.5V±2%, -Reset OCO
    Source
    Published code list

    Is it dead? The meter test is below: Integrated circuit.

  • XC6111B344MRSOT-23-5Voltage supervisor, 5 pins, TorexVoltage supervisorSOT-23-55 pinsTorex
    What it is
    Voltage supervisor
    Maker
    Torex
    Package
    SOT-23-5
    Pins
    5
    Details
    CMOS-IC: VDet 4.4V, -MR, -Reset PPO, Wt=100ms, Rt=25ms
    Source
    Published code list

    Is it dead? The meter test is below: Integrated circuit.

Is it dead? One meter test per kind

Parts of the same kind are tested the same way, so each test is here once. Each part above points to its own.

TVS or ESD protection diode

Diode range, from the protected line to ground, part lifted if you can.

Working, it reads

A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

Dead, it reads

  • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
  • A reading both ways on a one-way part: leaky.
  • A one-way part open both ways: failed open.
On the board
, a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
Compare:
The same part on the next line or connector pin is the healthy reading to compare with.
Watch for:
A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

Integrated circuit

Voltage with the board powered; ohms from each pin to ground with it off.

Working, it reads

Supply pin at its voltage and the output doing what the datasheet says. Readings between pins depend on the part.

Dead, it reads

  • A pin near 0 Ω to ground or to the supply pin where an identical part does not read that: failed short.
  • Supply present, output stuck: failed, or its load has.
On the board:
A pin shorted to ground on the board can be anything on that net. Lift the pin to be sure.
Compare:
The surest reference is the same IC on a working board, measured pin by pin.
Watch for:
Its protection diodes can read like junctions between pins, even like a transistor. That proves nothing either way.

A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

Printed with a code easy to misread as 77D

One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.

Codes that begin with 77D

For a marking with its end worn or burnt off. Each code has a page of its own.

Did you find your part?

Open this in the search to correct a character or try another package.