This is why you don't buy cheap multimeters.

[bluto]

Re: This is why you don't buy cheap multimeters.

Like this?

At least the place didn't burn. A couple of years ago around these parts, a charter subcontractor managed to burn down a brand new $2.5 million house by drilling into the electrical panel from the outside. It took 6 fire departments to put it out! This is the best link I can find...

http://www.ksdk.com/news/story.aspx?storyid=88193

Somewhere else it said the guy worked for 'Sparx' Communications

[ratdude747]

Re: This is why you don't buy cheap multimeters.

Apparently, one person thinks it is worth $100 Buy It Now on ebay.

http://www.ebay.com/itm/110818056416

Obviously, it didn't sell so he relisted it for $45.

http://www.ebay.com/itm/110820886299

him:

me:

they must be making crack more potent these days...

[kaboom]

Re: This is why you don't buy cheap multimeters.

...perhaps he went to the Verizon School of Math and his decimals are off...

Like this?

[severach]

Re: This is why you don't buy cheap multimeters.

YOU ARE BIDDING ON A NEW GEN-TECH DIGITAL MULTIMETER NEVER USED IN EXCELLENT SHAPE HAS ON/OFF SWITCH COMES WITH RED &BLACK METER READERS.

It's Cen-Tech. With spelling like that perhaps he went to the Verizon School of Math and his decimals are off. Could one of those meter readers be Peter the Meter Reader?

[retiredcaps]

Re: This is why you don't buy cheap multimeters.

My Harbor Freight $3 multimeter

Apparently, one person thinks it is worth $100 Buy It Now on ebay.

http://www.ebay.com/itm/110818056416

Obviously, it didn't sell so he relisted it for $45.

http://www.ebay.com/itm/110820886299

[Th3_uN1Qu3]

Re: This is why you don't buy cheap multimeters.

That's what it says on all meters, including my Uni-T ones which are fused. Never respected that and i haven't gotten a shunt catch fire yet, not sure how it affects accuracy tho. I've actually put 30A fuses in my Uni-Ts instead of 10A to avoid nuisance blowing.

[b700029]

Re: This is why you don't buy cheap multimeters.

There is no fuse for "10A" jack. To use safely, each measurement can not last for more than 10 seconds, and the interval between each measurement must be more than 15 minutes.

[momaka]

Re: This is why you don't buy cheap multimeters.


No wonder they don't put fuses for the 10A current setting - it's just not needed when the probes are acting as a fuse .

[Th3_uN1Qu3]

Re: This is why you don't buy cheap multimeters.

I bet the probes will melt at 5A.

4A actually. Melted a few myself.

[momaka]

Re: This is why you don't buy cheap multimeters.

Since my 99 cent 830 variant from ebay arrived DOA back in June 2010, these probes were NEVER used and have been put away. I took them out last week due to some of these threads and it literally fell apart in my hand.

Yep, cheap probes are cheap.
I was measuring some current last week with my 830D. After measuring about 1.7A for over 2 minutes, the wires on my probes were actually warm to the touch!
... and to think the meter can measure up to 10A. I bet the probes will melt at 5A.

[mockingbird]

Re: This is why you don't buy cheap multimeters.

Thanks for the model... Yea, I knew it was the IC, I was asking if he thought the IC was the culprit or maybe a diode or resistor was shot. I've read about transplanting these ICs, but like Unique said, for a $5 DMM... I dunno.

[retiredcaps]

Re: This is why you don't buy cheap multimeters.

Fuse is ok... Could it be the custom IC or you think it's a diode or transistor?

If you are talking about that black circular blob, that is a chip on board (COB). It is probably a ICL7106

http://www.hobby-hour.com/electronics/icl7106.php

[retiredcaps]

Re: This is why you don't buy cheap multimeters.

The LCD has some really weird connection, like some sort of plastic block with black things sandwiched in-between that somehow links it to the PCB... Does anyone know how that works?

That black/pink thing is a zebra stripe.

http://www.repairfaq.org/REPAIR/F_au...#AUDIOFAQC_012

For those curious, I figured out these are Sperry brand multimeters through some searching. Sperry DM-210A and DM350A.

[mockingbird]

Re: This is why you don't buy cheap multimeters.


And here is the PCB (Full size 300+ KB version is attached to this post)L


Fuse is ok... Could it be the custom IC or you think it's a diode or transistor?

[retiredcaps]

Re: This is why you don't buy cheap multimeters.

The LCD has some really weird connection, like some sort of plastic block with black things sandwiched in-between that somehow links it to the PCB... Does anyone know how that works?

Post some pictures please. I'm always curious to see the insides of any meter.

[mockingbird]

Re: This is why you don't buy cheap multimeters.

I have a DM210 and DM350, two real low-end meters... The DM210 works fine and I have had it now for a while... The DM350 I got recently. I turned it on and it was giving me very erratic readings. I opened it up, just to peek inside, and then I put it back together. I don't know what I did, but nothing comes up at all now. The LCD has some really weird connection, like some sort of plastic block with black things sandwiched in-between that somehow links it to the PCB... Does anyone know how that works?

Oh yea, the difference between them is that the 210 has only voltage and Ohm, and the 350 has a diode finction, so I have been using the 210 as a glorified battery tester.

[retiredcaps]

Re: This is why you don't buy cheap multimeters.

Uni-T makes pretty good stuff.

I'm thinking of getting a low end one (at the right price) just to see myself first hand what they are like. I have read most of the reviews here and at eevblog.

[retiredcaps]

Re: This is why you don't buy cheap multimeters.

This is a prime suspect - both the probes (either end) - and the banana sockets into which they plug.

Since my 99 cent 830 variant from ebay arrived DOA back in June 2010, these probes were NEVER used and have been put away. I took them out last week due to some of these threads and it literally fell apart in my hand.

Evidence.

And yes PeteS, I have much better quality name brand multimeters now.

[Th3_uN1Qu3]

Re: This is why you don't buy cheap multimeters.

In EU you can find Uni-T meters. Uni-T makes pretty good stuff. From bottom-of-the-barrel to Fluke level accuracy, they got everything covered. What you pay for is what you get. Uni-T is from China so no problems getting them in Asia either.

[PeteS in CA]

Re: This is why you don't buy cheap multimeters.

This is normal for the 830B and part of it is due to the crummy probes it comes with. With good probes it should read 0.6 to 0.9 ohms when shorted.

This is a prime suspect - both the probes (either end) - and the banana sockets into which they plug. I'm spoiled rotten - HP 73As are the "worst" DMMs in my test area, plus some Fluke 187s and some top-end Agilent handhelds. When you're trying to set voltages in the 4000 volt range to +/- 1 volt, a +/-1%, 3-digit meter is not adequate. I'm not the paying for the meters I use, while you guys are. Still, cheap @#$% meters will cost you more in the long run - in $$ and time wasted - than a Fluke 10, 20, 70 or 80 series DMM (also, look into Extech, which seems less expensive, but still decent quality). This is in the US ... not sure what's commonly available in EuroLand and Asia.