AiTrip LCR-T4 Mega328 Digital Transistor Tester Resistance Capacitance Diode Triode Capacitance Resistance ESR Meter MOS PNP NPN LCR with Case (No Battery)

Exactly what I was expecting. I had read and watched various reviews - including the one from Dave Jones at EEVBlog - and I was convinced it was worth picking one up. Especially important when one has a box of no-brand transistors and different manufacturers wire the emitter, base and collector differently for the same model. The included case and local US Prime delivery made this one worth the extra few dollars over getting one on ebay. Works great. I have been using it on the bench for doing some transistor and capacitor testing as well as some resistor categorizing from a grab-box I picked up recently. (Yes - I can read color codes ;-) but sometimes the bands on metal film blue cases can be tricky to distinguish for some colors). Seemed to fare pretty well compared to my digital multimeter. Make sure you follow the calibration instructions which you can find in various YT videos: in essence, hold down the button, short 1,2 and 3 with something - I used two breadboard jumpers - and then put in a capacitor when prompted. Above that - hats off to the vendor :-) The case had a small crack in the front plastic piece. I contacted them with pictures showing the issue and they didn't just send me a new front piece but a whole new unit. Excellent customer service - THANK YOU!

Please see my updated review at the bottom. Sorry this is a bit wordy, but it is for good reason. My review is based on perspective obtained from making my living repairing and designing circuitry in electronics products. Before I purchased this little gem, I saw reviews making critical comments about the contrast, the “supposed” issues with the plexiglass case, having to open the case when replacing the battery and so on. As someone who has worked on countless products, I thought it would be interesting to check out not only the operation and accuracy of this unit, but also why people complained about breaking or having to modify the case to fit, the contrast and so on. Being no stranger to quality test bench gear, I was very surprised at the quality and accuracy of this unit! For a mere $13, you get a transistor, diode and capacitor tester, unheard of just a few years ago. Electrolytic and tantalum caps are the worst offenders in the capacitor-world and this product does an excellent job of reporting their capacitance value AND ESR value! I had absolutely no issues with the case either….all pieces fit and interlocked together and it took maybe 10 minutes to get it together, most of that time was spent peeling off the protective covering! I found the contrast to be very acceptable and you can always change your viewing angle if it doesn’t suit you. You’re only needing to look at the screen for a few seconds anyway so I consider this another non -issue. Replacing the battery does requires removing the top of the case, but this unit times-out 30 seconds after a test so battery life should not be an issue, and when you do, it takes 5 minutes….remember, this cost $13 and does things a MUCH more expensive unit does. I’m not saying you’ll never need any other test gear, but I am saying those who complain are probably weekend warrior “tech” folks who are relatively inexperienced and can’t grasp the value this very inexpensive unit represents because they’ve never spent big money on test gear in the past, so understandably, they have a limited perspective, and if it dies in 6 months which I doubt, it is still worth it and I would purchase another one. For $13 you have a couple of choices, buy this or buy a couple of Fru Fru Lattes and see which one is around the next day. Enjoy! (see photos) UPDATED REVIEW: June 2025 The one important thing to be aware of is to discharge capacitors BEFORE measuring them, as the tester can/will be damaged by stored voltage that’s present on a charged cap. I knew to do this, but was working faster than usual one day and forgot and it’s now a mini doorstop😝 I recently bought another to replace it for just a few dollars more than the original and hopefully won’t forget again, but if I do they are inexpensive enough that I won’t feel bad about it.

This component tester works very well. I tried it on several components and it did an excellent job quickly and accurately measuring the component type and value. It even correctly measured a field effect transistor. The case it comes with is not terribly useful. It's finicky to assemble but sturdy once it's all together. The problem is that you have to disassemble the entire unit to replace the battery, and once in place the battery is unsecured so it rattles around. I ended up 3D printing a different case that overcomes those problems. All in all a good value for the money.

Good Little Transistor Tester- It was a little difficult to assemble but It very awarding to see how nice it looks after I assembled the enclosure. I installed a fresh battery and I tested a NPN and PNP transistor and it worked great.

Offers an interesting challenge in case assembly and device use since there are no instructions with the device. The device itself is fully assembled Notice the numbers 1, 2 , and 3 on the board. Use those connections for 2 and 3-lead components. Go online for as much detail as you need for this and similar devices. Uses standard 9-volt battery. Be careful to discharge capacitors - the microprocessor is sensitive to voltage on the terminals.