Best cheap transistor tester

As an Amazon Associate we earn from qualifying purchases. Details

Updated 23 October 2026

The best cheap transistor tester is the one whose listing names the parts you need to check, and whose safety rating suits your work. This roundup compares eight picks from a scan of twelve listings: five transistor testers and three 2-in-1 multimeters that add a transistor function. Work on mains circuits can kill. A meter’s CAT rating must suit the circuit, and panel or service work belongs to a licensed electrician. The scan holds no prices, so this post cannot say which listing costs least.

Quick answer

• Five of the eight picks are transistor testers. Three are multimeters that also check transistors and capacitors.
• Only the ZOTEK XT1 listing states a CAT rating in its text: CAT III 1000V and CAT IV 600V. None of the other seven picks states one, so none of them belongs on mains wiring.
• For a color screen and an SMD board, the FNIRSI LCR-P1 and the SORINA LCR-D2 listings both name that feature.
• Discharge capacitors before testing, and turn the circuit off before a continuity check. The Auxruen listing and the SparkFun guide give these steps.

Safety first for any transistor tester

The listings in this roundup describe bench-style component testers, and none says it is rated for mains wiring, outlets, panels or service conductors. The Purdue Extension sheet on voltage meters puts the core rule plainly: “Working with live electrical circuits can be very hazardous without proper tools and safeguards.” That line is about meters in general, and it applies to every tester in this roundup.

SparkFun’s multimeter guide sets the same boundary from the other side. It says “AC circuits can be dangerous.” Its continuity advice also gives the warning “Warning! In general, turn OFF the system before checking for continuity.” Follow both before you put any tester on a board that is still powered, or on a line that carries AC.

Fluke’s guide on test leads asks readers to “confirm that the DMM and test leads are rated for the category and voltage level appropriate for the electrical environment they will be used in.” The keyword in this post is about a low price, and Fluke addresses that directly: “Some may be a little more expensive, but safety and accuracy are not areas where cheaper is better.” A cheap tester with no CAT rating is still a cheap tester with no stated protection for mains work.

Panel, service and outlet wiring belong to a licensed electrician. This post gives no steps for working on live mains, outlets, panels or service wiring. For how a voltage tester reads a circuit before you touch it, read how voltage testers work.

What the listings state

The table below uses only what each listing spells out. Where a listing is silent, the cell says “not stated”. The scan record has no price field, so the table has no price column.

Pick	Model in the listing	Power source	Part types the listing names	Ranges the listing gives	CAT rating in the listing
FNIRSI LCR-P1	LCR-P1	Battery Powered	MOSFET, PNP, NPN, diode, Zener, R, L, C, ESR	not stated	not stated
diymore LCR-TC1	LCR-TC1	Battery Powered	NPN, PNP, n- and p-channel MOSFET, diode, thyristor, BJT, resistor, capacitor	not stated	not stated
Goldeep MT-1	MT1	Battery Powered	transistors, capacitors, resistors, NPN, PNP	capacitance 1pF to 100mF	not stated
Piilaamend LCR-MF10	MF-10	Battery Powered	capacitance, IGBT, inductance, MOSFET, resistance, SCR, diode, battery	DC maximum 0.2 A, AC maximum 0.1 A	not stated
ZOTEK XT1 (ZOYI)	not stated in the specs; bullets say ZT-XT1	Battery Powered	triode, diode, Zener, FET, JFET, IGBT, MOSFET, thyristor, SCR, TRIAC, resistor, capacitor, inductor	1000V DC, 750V AC, 10 A AC and DC, capacitance 1pF to 100mF	CAT III 1000V, CAT IV 600V
SORINA LCR-D2	LCR-D2 Electronic Component Tester	Battery Powered	transistors, diodes, triodes, FETs, Zener, capacitor, inductor, resistor	not stated	not stated
Auxruen LCR-MF10	LCR-MF10	Battery Powered	NPN, PNP, MOSFET, JFET, IGBT, diode, thyristor, triac, capacitor, inductor, resistor	capacitance 25 pF to 100 mF, resistance 0.01 to 50 MΩ, inductance 0.01 mH to 20 H, battery 0.2 to 40V	not stated
KELIN KK-05 PRO	KK-05 PRO	not stated	NPN, PNP, MOSFET, FET, SCR, diode, Zener, capacitor, inductor, resistor, ESR	not stated	not stated

Seven of the eight picks state a battery power source in their specification lines. The KELIN listing gives no power source line, though its bullets describe a rechargeable battery. Only one pick, the ZOTEK XT1, gives a CAT figure anywhere in its text.

The ranges column shows the most detail for the Auxruen listing, which gives low and high limits for capacitance, resistance and inductance. The Goldeep listing gives a capacitance range only. The Piilaamend listing gives current limits. The ZOTEK listing gives both voltage and current limits, and its current limit of 10 A is far above the 0.2 A DC maximum on the Piilaamend listing.

How a transistor check works in these listings

Most of the picks use automatic identification. You place the part in a socket, clip set or test board and press a key, and the tester works out the part type. The Auxruen listing describes this as inserting the part, locking the socket and pressing TEST, after which the screen shows the pinout and key values. The SORINA listing says a one-click scan shows the component type and pin sequence, and it adds an equivalent circuit diagram.

Automatic identification does not remove the need to read the result. A pinout on screen tells you which pin is which in the listing’s view, not whether the part is good. The listings give no pass or fail threshold for any transistor, so you still have to judge the reading against the part’s own datasheet.

Several of these meters also have a continuity mode. SparkFun describes continuity testing as “the act of testing the resistance between two points,” and says to look for “a diode symbol with propagation waves around it” on the dial. Two of the three multimeters name continuity in their bullets: the ZOTEK XT1 and the KELIN KK-05 PRO. The diymore, FNIRSI, Piilaamend, SORINA and Auxruen listings do not name continuity, so treat those units as part-identification tools rather than wire checkers.

how voltage testers work covers the basics of reading a voltage on a circuit, which is the step to take before any transistor check on a board.

The picks, one at a time

FNIRSI LCR-P1: color screen and SMD adapter

This pick suits a bench user who wants a color screen, an SMD adapter and IR decoding in one battery-powered unit. The listing names MOSFET, PNP and NPN checks, diode and Zener checks, R, L and C with ESR, a battery test and a NEC infrared decode. It states a 1.44 inch full-color screen, a 300 mAh battery and a Type-C port for charging and data. The replaceable patch seat is described as suiting both tiny precision parts and high-power devices. The anti-burn feature is described as discharging an undischarged capacitor when it is inserted. The limit is that the text gives no measurement range for the transistor or capacitor functions. Skip it if you need stated ranges before you buy.

diymore LCR-TC1: compact pick with IR decoding

This pick suits a desk user who wants a compact checker for transistors, diodes and capacitors. The listing says it detects NPN and PNP transistors, n-channel and p-channel MOSFETs, double diodes, thyristors, BJTs, resistors and capacitors. It has a built-in lithium battery that shows a green light when fully charged, an IR decoder that shows the user code, data code and waveform, and automatic shut-down with a manual off option. The weight is listed as 0.12 kg. The bullets warn that the charging input is 4.5V and that over-voltage will damage the tester. Its included-components line names only the transistor meter, with no leads listed. Skip it if you need a lead set in the box or a stated measurement range.

Goldeep MT-1: multimeter and component tester in one case

This pick suits a reader who wants a multimeter and a transistor checker in one unit. The title names a True RMS multimeter. The listing says the tester draws a component characteristic curve on a high-definition display, and that capacitance is measured from 1pF to 100mF with automatic identification of NPN and PNP types. It has a low-battery reminder, a metal probe jack and a box that includes test leads, a Type-C cord, a component board and a DIP chip socket. The text gives no voltage or current range for the multimeter side, so the True RMS name has no range beside it. Skip it if you need a stated voltage range before you buy.

Piilaamend LCR-MF10: current limits are stated

This pick suits a bench user who wants IGBT and SCR checks alongside the usual parts. The listing names capacitance, IGBT, inductance, LCR, MOSFET and resistance as measurement types, and its bullets add SCR and battery tests. It gives a DC maximum of 0.2 A and an AC maximum of 0.1 A, which is far below the 10 A the ZOTEK listing states. It includes test clips and a charger cable, and its bullets describe the same 1.44 inch screen and 300 mAh battery as the FNIRSI pick. Skip it for any current work above the 0.2 A DC figure, since the listing sets that as the maximum.

ZOTEK XT1 (ZOYI): the listing with a CAT rating

This pick suits a reader who needs a meter with a transistor check and a stated CAT rating. The safety bullet says the unit meets IEC standards with CAT III 1000V and CAT IV 600V. The multimeter side lists 1000V DC, 750V AC and 10 A AC and DC current, with a 25000-count display and a 1000 kHz range. The transistor side lists triode gain from 10 to 600, diode forward drop below 4.5V, Zener checks from 0.01 to 32V, FET types, thyristors, resistors, capacitors from 1pF to 100mF and inductors from 10uH to 1000mH. The bullets also give 36-month after-sales service. The name is inconsistent across the listing: the title says ZOTEK XT1, the brand field says ZOYI and the bullets say ZT-XT1, so confirm the model before you buy. Skip it if you want a small pocket checker, because the listing gives its weight as 191 g.

SORINA LCR-D2: pin sequence on a color screen

This pick suits a bench user who wants the part identified on screen. The listing says a one-click auto scan shows the component type, pin sequence and an equivalent circuit diagram on a color TFT. It names a detachable SMD test board, a DIP board, a dedicated Zener key and a side adjustment knob. The box includes the main unit, charging cable, DIP board, SMD board, probes and a manual. The protection line says the unit has multi-layer anti-burn and over-voltage protection against reverse wiring, residual charge and short circuits. No component value range appears in the text, and nothing in the listing mentions a CAT figure. Skip it if a published component range is a must for you.

Auxruen LCR-MF10: the most stated ranges

This pick suits a reader who wants numeric ranges on the screen. The bullets give capacitance from 25 pF to 100 mF with ESR and dissipation factor, resistance from 0.01 Ω to 50 MΩ, inductance from 0.01 mH to 20 H, Zener checks to 20V, and a white terminal for battery and DC checks from 0.2 to 40V. The display is a 160 x 128 TFT, and the unit has self-calibration, auto-off and a built-in rechargeable Li-ion battery. The limits are stated in the same listing: high-power IGBTs, thyristors and Darlington transistors may not identify correctly, and the IR decoder supports Hitachi-format signals only. Skip it if you need to decode a remote protocol other than Hitachi format, or if you need a current range, since the text gives none.

KELIN KK-05 PRO: 25000-count multimeter with transistor and LCR checks

This pick suits a reader who wants a 25000-count True RMS multimeter with a transistor and LCR function. The listing says it measures voltage, current, resistance, continuity, capacitance, inductance, diodes, MOSFETs, BJTs and batteries, and it shows real-time waveforms with custom alarm thresholds. It states a 2.4 inch TFT color screen, a rechargeable lithium battery with USB Type-C charging, ultra-fine probes and a replaceable test socket. The safety bullet names dual ceramic fuses and automatic capacitor discharge, but gives no fuse rating and no CAT figure. Skip it if you need stated CAT or fuse ratings before any work on powered equipment.

How we chose

We read the twelve records in the scan dated 23 October 2026 against three tests. The first test asks whether the title, highlights or bullets name a part that the tester checks. The second asks whether the record has enough text to quote, meaning a title, bullets or specification lines. The third asks whether the listing describes a component check, not only a plain voltage or current function. Eight records passed all three, five transistor testers and three multimeters with a transistor function.

Four more were kept off the cards, each for a reason in the listing text. The FORIOT LCR-AR1 lists its power source as Corded Electric, while its bullet describes a built-in 300mAh battery, so the listing contradicts itself. The ACEIRMC LCR-TC1 describes a 12864 green-backlit LCD in one bullet and a 160×128 TFT in another. The Cywhrvzsf LCR-P1 uses the same code as the FNIRSI pick, and its included-components line lists only a USB cable, so a second card for the same code would not help a reader. The FORIOT LCR-TC1 has general bullets with no measurement ranges, and its power source reads Corded Electric.

We did not add any product from outside the research record. We did not rank by price, because the scan has no price field. The word “cheap” in the keyword is not checked against any figure in this post.

What we could not verify

• Price. The scan record has no price for any listing, so the claim that a pick is cheap is not verified for any of the eight.
• CAT ratings for seven picks. The listing text gives no CAT figure for them, so none of them should be used on mains wiring, whatever their price.
• Accuracy. No pick gives an accuracy figure. Some listings use the word accuracy in general sentences only.
• Shared codes. The Piilaamend and Auxruen titles both carry LCR-MF10, and the FNIRSI and Cywhrvzsf titles both carry LCR-P1. The listings do not show whether each pair is the same device.
• Fuse ratings. The KELIN listing names dual ceramic fuses but gives no rating for them.
• Warranty. No pick states a warranty length. The ZOTEK listing gives 36-month after-sales service, which is a different promise.
• Transistor-specific theory. The three sources opened for this post cover voltage meters, continuity checks and test leads. None covers transistor measurement, so the transistor claims here come from the listings alone.

Mistakes to avoid

• Treating a tester as safe for household mains because it is cheap. Only the ZOTEK listing gives a CAT figure, and the other seven picks give none.
• Testing a charged capacitor without discharging it first. The Auxruen listing says to discharge capacitors before testing. The KELIN listing names automatic discharge, but the listing does not say that feature replaces that step.
• Expecting every high-power device to identify. The Auxruen listing says IGBTs, thyristors and Darlington transistors may not identify correctly.
• Assuming the IR decoder reads every remote protocol. The Auxruen listing limits its decoder to Hitachi-format signals, and the FNIRSI listing names NEC decoding only.
• Buying a current-capable meter for a higher current than the listing states. The Piilaamend DC maximum is 0.2 A.

Buying checklist

• Check the part types in the listing against the parts on your bench before you buy.
• Check the power source line. Seven picks state a battery, and the KELIN listing states none.
• Check the text for a CAT rating. If none appears, do not use the meter on mains wiring.
• Check the box contents. The Goldeep includes test leads and a DIP chip socket. The Piilaamend includes test clips and a charger cable. The Auxruen box lists only the transistor tester. The diymore box lists only the transistor meter.
• Confirm the model number when the title, brand and bullets disagree, as they do for the ZOTEK listing.

FAQ

Is a cheap transistor tester safe for mains wiring?

No, not on the basis of these listings. Only the ZOTEK XT1 states a CAT rating, and its listing gives CAT III 1000V and CAT IV 600V. Even that rating does not make panel or service wiring a home job. Work on those belongs to a licensed electrician.

Which picks suit surface-mount parts?

The FNIRSI LCR-P1 names an SMD adapter in its highlights, and its listing describes a replaceable patch seat. The SORINA LCR-D2 names a detachable SMD test board. The Goldeep MT-1 includes a component board and a DIP chip socket, and its listing names no SMD board. Check the box contents before you buy for SMD work.

Can I check a part that is still on a circuit board?

None of the listings says it works in circuit. The SparkFun guide tells you to turn the system off before a continuity check, and the Auxruen listing says to discharge capacitors before testing. Remove the part or power the board down first, and discharge any capacitor before you insert it.

Does any pick give a price or a warranty length?

No. The scan has no price field, so this post gives no price for any pick and cannot rank them by cost. For service terms, only the ZOTEK XT1 gives a length, 36-month after-sales service. No pick states a warranty length.

Do I need a multimeter, a transistor tester or both?

If you only identify parts, a transistor tester such as the FNIRSI or the Auxruen is the closer fit. If you also check voltage or current, the three 2-in-1 multimeters cover both jobs. For a broader comparison of multimeters, see best auto ranging digital multimeter and choose by the measurement you need most.

Bottom line

Start with the part types in each listing. If your parts appear in the listing, the tester fits your bench work. For any mains circuit, use only a meter whose listing states a CAT rating that suits the circuit, and leave panel and service work to a licensed electrician.

Sources

• Purdue University Cooperative Extension, 4-H Electric, Voltage Meter Basics: https://extension.purdue.edu/4-H/_docs/projects/electric/All-Levels-Voltage-Meter-Basics.pdf
• SparkFun Electronics, How to Use a Multimeter: https://learn.sparkfun.com/tutorials/how-to-use-a-multimeter/all
• Fluke, How to Test Multimeter Test Leads for Accuracy and Safety: https://www.fluke.com/en-us/learn/blog/digital-multimeters/testing-your-test-leads