My multimeter model is also DT-9205M as in the one in youtube video except that the case had different colors. I soldered the clamps myself before so that I do not need to touch the voltage line when I test a LED TV. So it may be due to my poor workmanship.

*** The multimeter may not as bad as I had thought. Have to buy some factory leads to test and use it again.

The resistance range I used is 'continuity' that got the reading around 024

One of the standard probes that comes with the package had broken.

Thank again for all the feedback.

 

Actually, yes, appliances that are old last a long time, new ones fail soon (because they are cheeeeply made).
My Name Brand DMM is very reliable and it is 35 years old.

 

When I buy a meter or any piece of TMDE (Test Measurement Diagnostic Equipment) I buy it for it's intended application or use. I have several DMMs to include very good to very inexpensive (cheap). Years ago one of my suppliers gave me an Omega Omegaette freebie. Works fine and has lasted over a decade now. I use it for general electrical work on my bike, the trucks, and residential wiring.

Here are the two meters side by side measuring a UPS Output while on mains power.


Now mains power is removed and this UPS outputs a MSW (Modified Sine Wave) waveform rather than a TSW (True Sine Wave).


Both measuring the same signal. Unless one plans to measure Non Sinusoidal AC wave forms the inexpensive meter does fine.

The described in the original post would have me looking for poor connections including in the actual leads.

Ron

 

Trite but true, you get what you pay for. I will try to differentiate between "cheap" and "inexpensive". Cheap being very poorly made and marginally safe vs. inexpensive, made safely and adequately performing. My less expensive meters, Aneng, AstroAI, etc. perform well and are reasonably accurate but take a while to settle, may drift a bit and maybe not as many samples/second as more expensive meters. My Fluke 27 is an antique by now, big, heavy, but settles fast with no drift and is accurate. It is also heavily constructed to withstand the rigors of constant daily use and abuse.

The described in the original post would have me looking for poor connections including in the actual leads.

Recently had an issue with one of my meters which turned out to be a cheap set of mini grabber leads. The banana jack end was a molded connecter which had developed an intermittent open. Once again you get what you pay for. Caveat Emptor

 

Looks like I had introduced 024 ohm resistance of the clamps when measured in continuity

 

My experience has been that much of the instability is in the connection at the meter probes. I have three very good meters, Fluke, Beckman, and Simpson, and with some cheap robes the readings wander and dance. But with decent quality probes the readings are rock-stable. AND some resistors have some sort of coating on the leads that makes a good connection challenging.

 

Here is a good video explaining why there are expensive multimeters.

 

Here is a good video explaining why there are expensive multimeters.

But presented by an idiot.

 

I bought a cheap digital multimeter but it seems unreliable. However, I do not have another one to compare with.
To start with, I connect a fixed value resistor to it and the reading range is at 200k ohm. As the reading goes up and down, see if you can figure out what is the value of this resistor from the video. Or do I have missed anything important from its manual about its usage?
And show me some videos of how your digital multimeter work. Is it works like that?
https://streamable.com/dt60vm

Never purchase a DVM without testing it against a known good one. Find someone at your local TV repair shop, or local electronics club, and ask them if they can help you confirm if your meter works or not. If bad, take it back, and see if you can have that person come along with their good meter and something to test a replacement meter with, at the store. Don't embarrassed, I've done it after purchasing 2 bad DVMs in a row. The store cannot prevent you from opening merchandise if you intend to by it if it's good. If it's bad, they cannot be expected to sell you a bad meter, so long as it is shown that you aren't damaging it- this is another reason to take a competent person with you, if you don't know how to check it.

 

Finally, in order to get my job done. I got a new 9V battery at shop.
The readings on my cheap multimeter is now more stable.

You can see from the picture, the cheap battery I got from a street stall has a 11-2019 date on its bottom, which is its expired date ( not manufacture date ). There is no out-of-battery indicated on the meter and it is measured 9.48V, but its reading is fluctuating up and down as in my video. Luckily, I get the new battery or I may throw away the meter.

In additional, this cheap meter will show a '1' on it if it is not within its measured range. So, one will not know how to use it without study the manual first. And you will need to do it step by step to estimate the measured value. When measured at the 2V range, there is no decimal point (is this a defect?) , so a reading like 1521 is thought to be 1.521V