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Review of the DY294 Digital Transistor Tester-Part 3

By on June 9, 2010

Here is the part 3 of the review of the DY294 Digital Transistor Tester:

Testing FET breakdown voltage:

Every transistor have a breakdown voltage  and this meter can be used to test on the N-channel and the P-channel Mosfet transistor. The test result were higher than the original value printed on the transistor spec. Please refer to the photos below for more information:

transistor tester

k1118 spec



 shorted fet

 testing fet

Testing SCR and Triac:

I found that the test result for SCR and Triac breakdown voltage were way out as compare to the device’s spec. This happen most probably because there is no gate signal present at the gate pin.

Testing Transistor Dc Current Gain hfe:

Sometimes a transistor can be tested okay with a normal meter but because of there is changes in the hfe value of the transistor, that particular transistor may not work when under full load. So it is equally important to test the hfe value as compare to just finding out the base, collector and  emitter pin  of the transistor. Below are the photos of the test result;

 testing hfe

testing transistor hfe

 testing transistor hfe

For your information, if the Horizontal Output Transistor (HOT) have a built in damper diode then this tester can’t test out the hfe value. It will just show “0.00” result.

What About Testing Other Transistor Parameter?

Well , the test result are more or less the same as testing the FET breakdown voltage. Just do not expect it to be exactly the same with the transistor specification downloaded from the internet.

Comment about this meter?

transistor manual

The disadvantage of this meter is that it does not have a proper probes to hold the components and you have to insert the components into the desire socket and this can cause the internal socket to loosen  easily. Second, external 6 volt 2 amp dc power supply may be needed to test on high power transistor. Third, the manual provided especially the connection of the components was quite blur. Since this meter is quite cheap and have the ability to test so many components, you have nothing to loose to own one.

Thank You

Jestine Yong




  1. ndsap

    June 9, 2010 at 10:56 am

    Hii Jestine,

    I have bought one and tested it and it works ok but the manual is blurr and I have to redraw it again.If you have time try to make a book on how to use an analog or digital oscilloscope,where and how to measure voltage and signal in a crt or lcd Tv or monitor.

    Thanks for your info.


  2. beh

    June 9, 2010 at 1:01 pm


    for sure Cameron is emerald of malezia . i wish you enjoy holidays
    with family there. and thank you so much for your efforts for third part report of DY 294 .but some questions:
    1-why test result of DY mostly is higher than the amount shown
    in data sheets . and can i trust to these results?
    2-on switch selector there is two position 79XX in pnp side and
    78XX on npn side what are these two good for?

  3. karlo

    June 9, 2010 at 1:57 pm

    Thanks for sharing jestine! How much is the meter?

  4. admin

    June 9, 2010 at 7:48 pm

    HI Karlo,

    Here is the link:

    I guess they have just increase the price from USD30 to USD55.00


  5. admin

    June 13, 2010 at 8:36 am

    Hi Beh,

    The test result were different most probably due the tolerance in the device. The 79xx is use to test on 79XX SERIES of voltage regulator IC and 78XX series is for testing the 78XX series of Voltage regulator.


  6. Russ

    June 24, 2010 at 7:59 pm

    Thank you Jestine for taking the time to write out the details of how to use this tester. I have one and I didn't even realize some of the things you pointed out! The manual is not very good so these instructions of yours are really helpful.
    Thank you

  7. admin

    June 25, 2010 at 6:02 am

    HI Russ,

    You are welcome!


  8. Sam C

    July 28, 2010 at 3:06 pm


    What do you think of this German Component checker / tester ?
    Original German presentation
    English translation (verbatim hard to follow)

    It checks transistors, N-channel P-channel enrichment/depletion MOSFET's, N-channel P-channel JFET's, Thyristor, Triac, simple and dual diodes and measures resistance (2ohms-20M), and capacitance (0.2uF-7000uF). Almost equal to the Peak Altas DCA55 and Atlas LCR Component Testers rolled into one !

    Please give me your expert opinion. I know you are a busy man but do go over the specifications thoroughly. I plan to build or buy one and will report my findings.

  9. admin

    July 30, 2010 at 8:32 am

    HI Sam,

    You are right it has the capabilities of Atlas DC55A and Atlas LCR Component tester roll into one. According to the website, checking capacitor was not accurate when you use this meter to test on a higher cap value. I suppose the microcontroller IC and lcd panel are not easy to get. If you could get those parts then i guess there will be no problem in building one. Do you intend to build one? By the way i did not see any link that they have a ready built unit for sale?


  10. Jeff

    October 3, 2010 at 9:15 am

    The DY294 meter is not very accurate for testing transistor gain because it does not have a constant current source. The displayed gain varies depending on the supply voltage (new batteries, weak batteries, AC adapter, etc). For example, if the supply voltage is 6.25V, the displayed gain might be 250, but at 5.50V, the displayed gain is only 220. In the 10uA base current setting with a 6V supply, I measured a current of only 9uA, so already a 10% error. The gain function is probably accurate only with a brand new set of batteries or a 6.5V adapter.


  11. admin

    October 3, 2010 at 9:21 am

    HI Jeff,

    You are right,this meter take up lot of batteries current and affect the reading. It is recommended to use the external dc supply which can provide a more precise result.


  12. Don koch

    November 17, 2010 at 10:50 pm

    Mr. Yong,
    I got your book and just can't be without it.

    I have a question about how to test Temperature Compensating Diode like the NTE 601 & 605A.
    Could you help me on how to test them.

  13. admin

    November 19, 2010 at 8:04 am

    HI Don,

    Do you have a photo how does this diode look like? You can send the picture to jestineyong(at)

    For most of the diode i would usually use an analog meter set to x 10k ohm and a good diode should have one reading.


  14. Amos Mponda

    March 12, 2011 at 6:39 am

    Hello Sir,
    I read all part 3 about the meter it seems to be very good meter i want to know the cost of the meter so as i can order it

  15. admin

    March 12, 2011 at 10:56 pm

    HI Amos,

    It is about USD55 excluding shipping charge.


  16. VIPIIN.V

    April 1, 2011 at 2:46 am

    Dear sir.............

    Pls provide the brief description of transistors.
    How to check the difference between the npn and pnp transistors?
    Pls provide this information to my email id

    Thanks and Regards

    Desktop service Engineer
    Accel It Resources Ltd
    Veekshanam Road
    Ernakulam North

  17. admin

    April 1, 2011 at 6:03 am

    HI Vipin,
    About checking the transistor i have compiled the information into an ebook at


  18. adnan jamil

    May 13, 2011 at 5:17 pm

    i think it,s practical to make a transistor tester with digital panel giving:
    1- type of transistor
    2-outlet identity b c e g1 g2 g s d
    4-voltage breakdown
    5- frequency of transition
    6- power opperating
    this tester must have a color monitor showing all data in some time and if possible gives multiple names americain + europeen

  19. Douglas Taylor

    June 29, 2011 at 6:23 pm

    I bought and received the DY294 transistor tester today. The user manual is the most useless manual I have ever seen. I thought the manuals that came with the MP3 players I bought from Uxell were bad, but this manual is not even written in English. If it had not been for your 3 pages of reviews you had written, I would never have known how to use this tester for anything but some basic transistor tests. Why do you think a company developing and marketing a testing device for distribution outside their own country, would not have taken the time to translate the manual into the language of the countries they would be selling to. You should write a full feature manual for this testing device and list it on your website. I would pay $10.00 for such a manual.
    I also was disppointed that this meter did not have test leads, but I thought I might open the case and solder leads on the terminals inside. Have to watch, when using the high voltage settings, that I don't touch any of those leads during testing.

  20. admin

    June 29, 2011 at 7:19 pm

    Hi Douglas,

    You are right about the manual-the words are small and blur and did not give full explanation on how to use this meter. Some companies are good in producing products but not necessary good in marketing or explaining how well their products could help us. In other words, not all products are user friendly but we still need those products because of low cost and have many features.
    I will try to contact the owner to see if they could come out with a better manual.


  21. ricko

    July 6, 2011 at 1:55 pm

    Hi Jestine,

    I bought a DY294 it worked for about 5 minutes then showed 1 on the display. The company sent me a replacement. So far it works good. I copied the manual into word as pictures and expanded the "pictures' it was then easily read. For the money the 294 seems like a good deal. I use it to help identify semiconductor die.

    Best regards,

  22. admin

    July 7, 2011 at 3:42 am

    Hi Rick,

    Thanks for the update.


  23. Phill

    August 21, 2011 at 9:29 am

    Hi Jestine,
    Have you tested Germanium transistors on the DY294?


  24. admin

    August 22, 2011 at 8:47 am

    HI Phill,

    Nope i have not tested it yet because my side here does not have the Germanium transistors.


  25. bob lou

    March 24, 2012 at 5:21 pm

    Thanks Jestine for all you help...I'm currently working on a TV that has a FET transistor in the Power Supply and want to try to test it using this meter. It's looks to be very useful and it's something I can afford.

  26. Reza

    June 23, 2012 at 3:13 pm

    ich habe auch diesen Tester von Ihrer Firma gekauft und das Problem, das das Handbuch auf chinesich ist. alle Versuche es mit einem Übersetzungsprogramm zu übersetzen sind fehlgeschlagen.
    Gibt es eine Webseite wo das Handbuch in englisch verfügbar ist?

    • Amendar

      October 12, 2013 at 5:41 pm


      Haben Sie das Handbuch in Englisch gefunden?


      • Jestine Yong

        October 12, 2013 at 5:47 pm

        Hi Amender,

        Try this link:


  27. Reza

    June 23, 2012 at 3:17 pm

    es würde mir auch schon helfen, wenn das handbuch im internet veröffentlicht wäre und ich die Seitenadresse hätte.

    • Jestine Yong

      June 26, 2012 at 8:07 am

      Hi Reza,



  28. Wimpie

    September 27, 2012 at 9:53 am

    Hi Jestine
    I also used mine for about 5minutes and mine also suddenly show a 1 on the screen.I emailed them and waiting for a reply from them.Looks like this is a common fault on these testers.

  29. Jack

    July 18, 2014 at 12:26 pm

    Hello jestine, what is this meter can't measure hFe transistor that have damper diode (protection diode) as in RF power transistor at all? I interest with this meter for measuring hFe of RF power transistor. thanks for your reply

    best regards

    • Jestine Yong

      July 18, 2014 at 8:14 pm

      HI Jack,

      Try visit


  30. Sanjeev Gaurav

    June 5, 2023 at 2:27 am

    Digital Inverter Wi-Fi Enabled Side by Side Refrigerator


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