I did a review and teardown of an HT118A multimeter. It is a rather generic 6000 counts true RMS auto-ranging meter. If you have not watched the video of this review, please check it out below. I also did a separate teardown video and mainly wanted to check out the quality of the build and the validity of the claimed CAT III and CAT IV ratings.

Here is the video of the review:

And here is the video of the teardown:

Below is a picture of the meter out of its plastic holster. The holster itself fits on rather tightly and it was very difficult to remove.

The case was secured by four self-tapping screws. The battery cover does have a machined screw in place.

One thing apparent is that the input has no protection MOVs, which would almost certainly be required if it was a true CAT III/CAT IV rated meter. My advice is that these no-name branded meters should only be used for electronics work even if they claim to be CAT III/CAT IV rated.

From the picture below, you can see the light pipes used to illuminate the sockets. this is a rather cleaver design.

The HT118A uses two AA batteries, which is very convenient.

Here are a couple more pictures showing the component side of the circuit board. The fuses used are clearly not HRC type, another reason for not recommending using this fuse for electricians work.

I don’t know what exactly is the main DMM chip used in this multimeter. It could be a DTM0660 or its variant based meter given the similar board component layout compared to that of the ennoLogic meter I had. The DTM0660 is highly hackable by changing the configuration settings in its companion EEPROM.

Below are a couple of pictures of the other side of the board.

Finally, here are a couple of pictures of the LCD used in this multimeter.

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21 Thoughts on “Teardown Pictures of an HT118A Multimeter”

  • I’ve ordered this product and waiting for it to arrive.
    I hope there would be a way to change mV range to 60.00 and adding relative and manual range functionalities to it (maybe assigning them as long press func and hold?) via modifying EEPROM.
    I wish you had a Discord server so we could discuss these matters with other users.

  • Kerry,
    I purchased this very DVOM a year ago and so far I have been pleased, with the exception of the back-light. It times-out in 15 seconds! Are you aware of any “hack” or modification that can be performed to the HT118A to keep the back-light on longer OR indefinitely???
    Many thanks for your time!

    • Unfortunately, since I don’t know the DMM chip used here. If you happen to know please let me know as well as most of these DMM chips have the configurations stored in an EEPROM and can be reprogrammed if I know how to interpret the data.

  • Recently purchased one of these to replace a functioning Greenlee basic DVMM bought at Lowe’s years ago. Using an MFJ269C Antenna Analyzer as a signal generator and a Rigol digital oscilloscope compared voltage and frequency readouts with the HT118A meter. They were very close at < or = 1%. I like the bigger numbers since I am an old guy! The temperature readout is quick and equal to analogue thermometers. There are several features either different or ignored in the operating manual but what else is new? Like the backlight changing to red! The Kaiweet version claims they will replace the meter if the fuse gets blown! Should be a good meter if it lasts as long as the Greenlee.

  • I managed to blow the fuse on my meter. However, I see no access screws to remove to get inside to the fuse. Even removed the batteries, still no screws. How do I open the case to replace the fuse?
    Thanks.
    Bill

  • Can’t measure capacitance anymore.

    I have this exact meter and all of a sudden the meter reads 0 on all capacitance readings. What could of happened? I have opened it and fuses are good, nothing looks burnt or damaged.
    Also changed the batteries just to be sure but still it can’t read capacitance anymore.

    Where to start? I was thinking that shiny silver looking thing (its a cap maybe?) around the J2 marking might be worth measuring, but i dont know what it should read if its working or not working. Also I don’t even know what it does or what it’s for.

    Everything else still works fine. Just every capacitance reading started showing zero. It wasn’t like this from the start though, I used to be able to measure capacitance as well. Have had this for a while and I don’t think I have any warranty left.

    I suppose it applies a small voltage to the capacitor and then reads the result, perhaps its failing at applying that voltage, however I can’t figure out how it does it and what could be faulty.
    I guess something has shorted out without it being visibly damaged.

      • Hi, thanks for replying.
        Sure maybe, have done some reading on caps, I always try to remember to discharge them first, but I can definitely have forgot it once. Only smaller capacitors on computer pcbs though. But maybe it was enough to damage it.

        If that was the case do you have any idea what could have been shorted out? That resistor on the bottom of the board R005, can it become overloaded? Is it suppose to read 0.005 Ohms?
        It reads 0.0 Ohm on my mm but I don’t think my it can read 0.005.
        I suppose I should probably take it out of the board to get accurate reading.

        Also that silver shiny piece, while still on the board it reads: 1 Mohm and and when checking capacitance it reads 0.05 nF. Don’t know what this means though.
        Also while on board, those two green PTCs read 1.2 and 1.3 kOhms.
        All the 5 diods next to the PTCs pass the multimeter diode test, that is multimeter is beeping when measuring in diode mode in one direction and when switching probes not beeping.

  • It means that for some reason the signal generator in the meter has quit working. This generator makes capacitance readings possible. Confirm this with an oscilloscope or another multimeter that can read frequency higher than 60 hz.

  • Kerry and Jay

    The capacitance function of this meter is dependent upon an onboard oscillator. No oscillator = no farad reading. Yo can verify with either an oscilloscope or a multimeter with a freq counter like the 118A. The meter I have “scopes” at 19 khz with no capacitor and that reduces with an increase of capacitance under test. So this means the frequency counter is also employed in determining capacitance.
    Jay, does your freq counter still work?

  • Okay, so I’ve never used a frequency function on a MM so don’t really know how to use it, I can see there are three options of Hz on the multimeter, at the V and mV settings and one that says Hz %.
    I put it on Hz % and in lack of figuring out things to measure I tried my headphone cable and it showed 50Hz, pretty steady around 50Hz, slightly fluctuating, and with my other multimeter (Klein Tools MM400), it also showed 50Hz maybe somewhat more steadily, so it seems frequency function is working.
    I didn’t understand what you meant with testing at 19khz with no capacitor or how to test the frequency counter.
    Was this a frequency counter test? If not how can I test it? I don’t own an oscilloscope.

    • Your other meter can display frequency. Put your HT-118A on capacitor. Hook the leads to your other meter set to hertz/frequency/AC Volts (with frequency readout) and see what your other meter says about the frequency output of your HT-118A.

      • Oh ok I see, so on my other meter if I put it on AC volts it shows 0 volts.
        When I put it on Hz it shows 18.64 kHz very slowly decreasing.
        When I put it on % Duty cycle it shows 40.

        I can’t find a setting on MM400 that has AC volts with frequency readout like the HT118A has.

  • Okay, just use the hz position. The freq on this one is fairly stable until a capacitor is placed across the leads. The freq then immediately reduces to some value and is stable at that freq as long as the cap remains.

    That initial frequency should be stable, in my opinion. The meter is defective if it slowly decreases.

    • Well it starts off showing 18.64 and after a few seconds showing 18.63 and so on.
      If turned around, checking the frequency with the HT118A on the MM400 in capacitance mode (this one has working capacitance) it does the same thing. However it starts at around 5 kHz instead and same thing there, the last decimal is very slowly decreasing in about the same rate.
      That seems to me that it might be nothing wrong and still decrease slowly in this way.
      Maybe it’s not frequency function thats faulting, no idea what it could be though.

  • Retested my HT-118A with o-scope and the freq dithers between 19.35 and 20.3 khz with a majority of the time at 19.69 khz. The reading on the screen of the meter is a steady .103 uf. The meter shows .012 nf with just the test leads laying close together. Time for a warranty replacement! Supposed to be guaranteed 3 years.

  • Yes and since I haven’t found anything obvious that’s easy to replace I’m just sending it back. At first I thought it was only 1 year warranty.

    I do have the Klein Tools multimeter which I have actually used much more extensively for a longer time, it seems its very nice and maybe feels more durable in general (I know I can’t really decide that in just these 2 samples, it’s just a feeling really) however it has alot less range on the capacitance than the HT118A so still need something with more range.

    I have now sent the HT118A back. Not sure if I should try and get same model again or just refund.
    I did notice that the pictures here has board version v. 1.8B, whereas mine if I recall had version v. 1.3. printed.
    So one thought is that some things might of been improved on board design etc since v 1.3. But maybe it’s just minor things that you really wouldnt notice.

    Thanks for all the help here.

  • Anyone have a schematic of the 118A? I burned the ma and ua scales. Replaced two 1N4007 diodes but there are two resistors somewhere that must have got it, too. Need where and what values.

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