Skip to content

SMD code search: identify a part by its marking

2 parts are printed Z30B. 2 printed with a similar-looking code.

2 parts are printed Z30B

Not sure which one you have?

Answer up to 4 quick questions and these 2 parts are ranked, with a meter test that settles it. It works on a dead part too.

Zener diode, all SOD-80, 2 pins. What differs:

  • TLZJ30BSOD-80Taitron ComponentsTaitron Components
    What it is
    Zener diode
    Maker
    Taitron Components
    Package
    SOD-80
    Pins
    2
    Details
    SMD Zener Diodes (Leadless ) - 500mW
    Source
    Manufacturer datasheet

    Is it dead?

    Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

    Working, it reads

    About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways, forward too: failed open.
    • Holds well off its rated voltage on the supply test: drifted.
    • A soft knee, or a voltage that creeps on the supply test: leaky.
    On the board
    this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

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

  • GLZJ30BSOD-80PanjitPanjit
    What it is
    Zener diode
    Maker
    Panjit
    Package
    SOD-80
    Pins
    2
    Details
    Zener diode: 27.70..29.13V, Zzt=55 , Izt=5mA, 500mW
    Source
    Published code list

    Is it dead?

    Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.

    Working, it reads

    About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways, forward too: failed open.
    • Holds well off its rated voltage on the supply test: drifted.
    • A soft knee, or a voltage that creeps on the supply test: leaky.
    On the board
    this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.

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

2 more parts are printed with a code easy to misread as Z30B

Printed with a code easy to misread

One character differs, and it is one that is easy to confuse under a lamp. The odd one out is marked on each.

  • S2308Aprinted 2308SOT-23-6MOSFET, 6 pins, Yangjie Electronic TechMOSFETSOT-23-66 pinsYangjie Electronic Tech

    Printed 2308 on the part. Easy to misread as Z30B. Check that character with a loupe before you order anything.

    What it is
    MOSFET
    Maker
    Yangjie Electronic Tech
    Package
    SOT-23-6
    Pins
    6
    Source
    Manufacturer datasheet

    Is it dead?

    Diode range, part lifted. Test drain to source first, then short gate to source and test again.

    Working, it reads

    One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

    Dead, it reads

    • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
    • The gate reads low to source or drain: gate shorted.
    • No body diode at all: failed open.
    On the board
    the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

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

  • CD214B-B230printed 230BSMBSchottky diode, 2 pins, BournsSchottky diodeSMB2 pinsBourns

    Printed 230B on the part. Easy to misread as Z30B. Check that character with a loupe before you order anything.

    What it is
    Schottky diode
    Maker
    Bourns
    Package
    SMB
    Pins
    2
    Details
    Diode: SBR, 30V, 2A, Vf<0.5V(2A), <200pF
    Source
    Published code list

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.15 to 0.45 V anode to cathode, roughly half a silicon diode, and open the other way.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • A reading the wrong way round as well: leaky.
    • Open both ways: failed open.
    On the board
    this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A large Schottky can read about 0.1 V forward and beep like a short, and leaks a little the wrong way when good, more when warm. It is shorted only if it reads the same both ways. Measure it cold, beside an identical cold one.

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

12 more parts have codes that begin with Z30B

Codes that begin with Z30B

For a marking with its end worn or burnt off. Each one shows its full printed code.

Voltage supervisor. What differs:

  • BL8509-230BCRMprinted 230BCSOT-233 pins, Shanghai BellingSOT-233 pinsShanghai Belling

    Printed 230BC. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Shanghai Belling
    Package
    SOT-23
    Pins
    3
    Details
    Voltage detector IC: 2.3V±2%, -Reset PPO, Rdt=100ms
    Source
    Published code list

    Is it dead?

    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.

  • BL8509-230BCRNprinted 230BCSOT-23-55 pins, Shanghai BellingSOT-23-55 pinsShanghai Belling

    Printed 230BC. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Shanghai Belling
    Package
    SOT-23-5
    Pins
    5
    Details
    Voltage detector IC: 2.3V±2%, -Reset PPO, Rdt=100ms
    Source
    Published code list

    Is it dead?

    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.

  • BL8509-230BNRMprinted 230BNSOT-233 pins, Shanghai BellingSOT-233 pinsShanghai Belling

    Printed 230BN. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Shanghai Belling
    Package
    SOT-23
    Pins
    3
    Details
    Voltage detector IC: 2.3V±2%, -Reset ODO, Rdt=100ms
    Source
    Published code list

    Is it dead?

    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.

  • BL8509-230BNRNprinted 230BNSOT-23-55 pins, Shanghai BellingSOT-23-55 pinsShanghai Belling

    Printed 230BN. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Shanghai Belling
    Package
    SOT-23-5
    Pins
    5
    Details
    Voltage detector IC: 2.3V±2%, -Reset ODO, Rdt=100ms
    Source
    Published code list

    Is it dead?

    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.

  • GM8509B-230BCRMprinted 230BCSOT-233 pins, Hangzhou Jiemao MicroelectronicsSOT-233 pinsHangzhou Jiemao Microelectronics

    Printed 230BC. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Hangzhou Jiemao Microelectronics
    Package
    SOT-23
    Pins
    3
    Details
    Voltage detector IC: 2.3V±2%, -Reset PPO, Rdt=100ms
    Source
    Published code list

    Is it dead?

    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.

  • GM8509B-230BCRNprinted 230BCSOT-23-55 pins, Hangzhou Jiemao MicroelectronicsSOT-23-55 pinsHangzhou Jiemao Microelectronics

    Printed 230BC. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Hangzhou Jiemao Microelectronics
    Package
    SOT-23-5
    Pins
    5
    Details
    Voltage detector IC: 2.3V±2%, -Reset PPO, Rdt=100ms, Td-Disable
    Source
    Published code list

    Is it dead?

    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.

  • GM8509B-230BNRMprinted 230BNSOT-233 pins, Hangzhou Jiemao MicroelectronicsSOT-233 pinsHangzhou Jiemao Microelectronics

    Printed 230BN. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Hangzhou Jiemao Microelectronics
    Package
    SOT-23
    Pins
    3
    Details
    Voltage detector IC: 2.3V±2%, -Reset ODO, Rdt=100ms
    Source
    Published code list

    Is it dead?

    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.

  • GM8509B-230BNRNprinted 230BNSOT-23-55 pins, Hangzhou Jiemao MicroelectronicsSOT-23-55 pinsHangzhou Jiemao Microelectronics

    Printed 230BN. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Hangzhou Jiemao Microelectronics
    Package
    SOT-23-5
    Pins
    5
    Details
    Voltage detector IC: 2.3V±2%, -Reset ODO, Rdt=100ms, Td-Disable
    Source
    Published code list

    Is it dead?

    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.

  • LC9009CB3TR230BCprinted 230BCSOT-233 pins, Shanghai LeadChip MicroelectronicsSOT-233 pinsShanghai LeadChip Microelectronics

    Printed 230BC. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Shanghai LeadChip Microelectronics
    Package
    SOT-23
    Pins
    3
    Details
    Voltage detector IC: 2.3V±2%, -Reset PPO, Rdt=100ms
    Source
    Published code list

    Is it dead?

    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.

  • LC9009CB3TR230BNprinted 230BNSOT-233 pins, Shanghai LeadChip MicroelectronicsSOT-233 pinsShanghai LeadChip Microelectronics

    Printed 230BN. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Shanghai LeadChip Microelectronics
    Package
    SOT-23
    Pins
    3
    Details
    Voltage detector IC: 2.3V±2%, -Reset ODO, Rdt=100ms
    Source
    Published code list

    Is it dead?

    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.

  • LC9009CB5TR230BCprinted 230BCSOT-23-55 pins, Shanghai LeadChip MicroelectronicsSOT-23-55 pinsShanghai LeadChip Microelectronics

    Printed 230BC. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Shanghai LeadChip Microelectronics
    Package
    SOT-23-5
    Pins
    5
    Details
    Voltage detector IC: 2.3V±2%, -Reset PPO, Rdt=100ms
    Source
    Published code list

    Is it dead?

    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.

  • LC9009CB5TR230BNprinted 230BNSOT-23-55 pins, Shanghai LeadChip MicroelectronicsSOT-23-55 pinsShanghai LeadChip Microelectronics

    Printed 230BN. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    Voltage supervisor
    Maker
    Shanghai LeadChip Microelectronics
    Package
    SOT-23-5
    Pins
    5
    Details
    Voltage detector IC: 2.3V±2%, -Reset ODO, Rdt=100ms
    Source
    Published code list

    Is it dead?

    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.

Did you find your part?

Try Tech free for 30 days. You need a card to start. Unless you cancel during the trial, Tech then costs €12.00 a month plus VAT. See the plans

One code, several parts

Marking codes are not unique. In the standard code book, 6H on a SOT-23 is an NPN transistor, a varicap, an N-channel JFET, two digital transistors, a 3.6 V voltage detector: six parts from five makers. So a search on WhatSMD (What SMD) shows the parts we hold under that code and under codes easily misread as it, with only the columns that tell them apart.

6Hon a SOT-23, in the code book
  • NPN transistor
  • Varicap
  • N-channel JFET
  • Digital transistor ×2
  • 3.6 V voltage detector

When more than one is left

Tap Help me choose. Up to 4 quick answers: whether the part has failed, then what separates the parts left. Those get ranked with the reasoning and a test that settles it. That uses one identification: 2 a month are free without an account, and 3 with a free account.

When you cannot read it

Tap the camera in the field. We read the characters, keep the ones we are unsure of, and search every reading. A photo too soft to read is turned back on your phone first; if it is the only one you can get, you can still send it.

Get the app

The same search on your phone, and a camera with a light, zoom and tap to focus for a marking you cannot read. Sign in with your email address to use the same account.

  • Get WhatSMD on Google Play
  • Coming soon to the App Store