Is it me or does everything ending with …tech goes berserk on me?

[Spawn]

I got a Mastech MS2108A clamp meter from ebay, it arrived today so I was playing around with it for a review I want to do. The meter was surprisingly accurate compared with my other meters, AC current and DC current was going well between 1.5A and 6A, voltage measurements where spot on.

Then I took out the leads was checking its functions, and turning the rotation switch suddenly display goes out, I can’t remember which position the rotation switch was but I turned off and turned back on, when I got in 40A current mode something blew up inside! I hear suddenly a little explosion and meter start to work, did some measurements everything works only DC current mode shows constant reading between 1.5A till 2A and if I try to measure something it goes to 0.000

I was like “WTF” so I opened up the meter and one of the tantalum capacitors was blown 

I couldn’t see anything wrong in there which could cause this, only thing I seen was that the flat cable running to the clamp was stuck in the housing when they mounted together, but there was no damage. To be honest I was impressed with the measurements I did, this is just a bummer. I don’t think it is something common because I couldn’t find anything on the net similar to this.

I send a email to Mastech let’s see what they have to say.

Lightages if you are reading, remember when you recommend me the MS2108 (without A) and I said something about brands ending with …tech hahahaha 

[Lightages]

I am reading.... I am sorry to see your problem. If I recommended the MS2018 it was only from what I have seen online. I hope the one I have on the way doesn't blow up too!

There is a well known problem with tanatalums as you probably know. They can be little fires waiting to happen. They have great characteristics but one of the bad ones is that they can be quite unreliable and fail in the worst way sometimes. Before I would blame Mastech I would blame the company the got their capacitors from. They might even have supplied fakes. This has happened to the best of companies as did happen to many well regarded motherboard manufacturers in the past.

It is obvious that you should get a full replacement from Mastech without any questions asked. I hope it goes well for you.

[GK]

I'm wondering if it was soldered in the wrong way. Just out of curiosity it might be a good idea to power it on and measure the polarity of the voltage between the pads.

[amyk]

The two intact ones slightly to the right of bottom center both have one end connected to the same net but are opposite polarity... might want to check that too (it could be OK if it's something like negative supply though).

[notsob]

I were you I wouldn't be going out and getting a vas-tech-tomy right now

[PA0PBZ]

The two intact ones slightly to the right of bottom center both have one end connected to the same net but are opposite polarity...

As I see it they are connected the same way as the burned one, with the negative side to the same trace.

[Spawn]

I am reading.... I am sorry to see your problem. If I recommended the MS2018 it was only from what I have seen online. I hope the one I have on the way doesn't blow up too!

Don’t be sorry, I am laughing at this problem right now. I don’t blame Mastech either meter was 42USD so not that expensive, but you will see how solid it feels when you receive your MS2018A, it is nice feeling clamp meter.  I seen a video with quick glance of the PCB of MS2018 and it has less tantalum capacitors.

 

I'm wondering if it was soldered in the wrong way. Just out of curiosity it might be a good idea to power it on and measure the polarity of the voltage between the pads.

Thanks for the suggestion, I checked polarity already on the traces and that seems to be okay, besides it was working before all evening with the measurements.

I were you I wouldn't be going out and getting a vas-tech-tomy right now

LOL,    you are probably right, till couple months ago only meters I got except Fluke’s and Gossen Metrawatt,s where from Voltcraft, I am in search for cheap alternatives to review and maybe prove “the bigger brand meters are only thing you should get” theory wrong.


If I don’t get any response from Mastech I might try to replace it but the value is gone, most are 10u 16v on the PCB. We will see.

Here is the complete board:

[flolic]

I have the same clamp meter so I can check that value for you 
But is is most likely 10uF/16V

[Spawn]

That would be great if you do that for me , but no hurries got enough time, thanks )

Posted from mobile phone with taptalk.

[flolic]

It is 10uF/16V capacitor 

[Spawn]

Great, thanks a lot! 

You got different manufacturer capacitors there, maybe those will last longer.

[flolic]

I hope so 

[Spawn]

I am waiting on a response from Mastech, since Chinese New Year vacation started I will give them two weeks. If they won’t answer I will replace the capacitor, I hope it was only the capacitor and not something else too.

[Spawn]

Update about Matech’s respond, Mastech contacted me after my second mail and redirect me to a distributor in Germany, I have send a mail to the German distributor and they say they don’t give support to equipment which is not sold by them, so I am not even going to bother to mail Mastech again, going to order tantalum capacitor and replace myself in the hope that the only thing is which is blown. 

[Spawn]

   Another news, now suddenly eBay seller contacted me, he was away and he is offering to replace it, I told him, it is too expensive to send it back so he offered me to pay 20 USD for a new one and I can keep the broken one.  I already give a good feedback when I tested it first day so it is nice to see a seller trying to be helpful even after a feedback.

When I receive the new one I will do a review of it.

I got it from here: http://www.ebay.com/itm/180920154415

[G7PSK]

I got one of those last year, very accurate for the price and even reads HZ while in the amps mode (which is useful for me to check power plant without electrical contact) what I have noticed is that on occasions the meter does not come on when switching from one range to another, rotate switch back and forth and it works, I expect that a squirt of switch cleaner is all that is required but have not taken it apart yet. For the price (£26-51 inc.p&p) it cant really be beaten if it blows up I bin it. The probes have a very nice feature, the tips protrude through the plastic covers just enough to make contact on chips etc. without the risk of shorting out adjacent leads.

[Lightages]

I finally received my Mastech MS2108 with TRMS. The board inside is different. I will be doing a full review on my recent two cheap clamp meters but before then I want to let you know of another problem. Those flat flex cables are very very fragile on these meters at the solder points. I had to replace one in mine after taking the circuit board out a couple of times. Just watch out for that.

[Wytnucls]

UNI-T uses those flex cables too, but with proper connectors:
I dont think the flex ribbon wiring is designed for PCB soldering anyway. Not impressed with Mastech!

[Spawn]

Connectors looks same to me Wytnucls, Lightages is talking about the flat cable itself, I think the one for LED torch light, that’s the only one soldered.

 I don’t understand why they put that torch light anyways, if you go measure high current in a dark room, you should let your head get checked. It is just too fancy things up I guess, it looks nice on the package when you tell it has a torch light.

I am going to review this one too Lightages, got a new camera now for better quality video and sound, with one of the last reviews I made, I couldn’t understand myself, let alone other people.

[Wytnucls]

Yes, I see that now, but they should have installed a proper connection gizmo for those 2 flat cables too.
Soldering directly to the PCB looks really tacky.
Something like this:

[Spawn]

I can’t agree more with you there, for all I care they could leave out that useless LED torch and it would look a lot cleaner inside

[Lightages]

Yes I was referring to the two conductor ribbon for the torch. I can see the torch being useful as not all distribution boxes are well lit inside. It is an added aid to getting the jaws around the right wire.

[Spawn]

Hmmm, Lightages I agree on most things with you on the forum  but on this torch light I don’t because you need a good light source when you measure current in a distributor, sure it could be handy but when I see the light output I wouldn’t rely on it in a distributor box.

(I hope Fluke haters won’t shoot me when I say this but… ) I never seen one on a Fluke or high end clamp meter either, I know you can’t compare this to a Fluke so I don’t want to start a discussion about that here, just giving example, maybe I am wrong but profession wise it is better to use another light source.

[Lightages]

Don't worry, we still agree. I was just coming up with a use for the torch that was possible, not usual.