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Products => Test Equipment => Topic started by: Ochsenfrosch on May 25, 2017, 07:35:22 am

Title: Opening a Testboy TB-3000
Post by: Ochsenfrosch on May 25, 2017, 07:35:22 am
Hi, I opened my Testboy TB-3000 multimeter. It's about 70,-€ in Germany.
Have some impressions.
Title: Re: Opening a Testboy TB-3000
Post by: Fungus on May 25, 2017, 07:44:41 am
It might just be the angles, but...these look awfully close to each other on the input protection. I think a spark might be able to jump that distance.

(https://www.eevblog.com/forum/testgear/opening-a-testboy-tb-3000/?action=dlattach;attach=318402;image)

And the soldering...  :wtf:
Title: Re: Opening a Testboy TB-3000
Post by: Fungus on May 25, 2017, 07:47:43 am
Looks like someone cleaned their soldering iron at the current shunt...
(https://www.eevblog.com/forum/testgear/opening-a-testboy-tb-3000/?action=dlattach;attach=318400;image)

That's called "calibration".

Looks like the resistance was a little bit high so they added some extra solder to fix it.  :popcorn:

TÜV Süd/GS approved

The design looks OK but I bet the meter they submitted for approval wasn't soldered/assembled by the same person that soldered/assembled yours.
Title: Re: Opening a Testboy TB-3000
Post by: Towger on May 25, 2017, 08:07:30 am
That's called "calibration".

To quote  Dave, it is done by nude virgins or old gray beards with their tongue the correct angle.  But, I think you are correct, in this case old Bathild looked at the meter in a test rig and cleaned the tip of her soldering iron on the shunt.
Title: Re: Opening a Testboy TB-3000
Post by: Fungus on May 25, 2017, 08:46:16 am
That's called "calibration".

To quote  Dave, it is done by nude virgins or old gray beards with their tongue the correct angle.  But, I think you are correct, in this case old Bathild looked at the meter in a test rig and cleaned the tip of her soldering iron on the shunt.

No, it's true!

Normally they're manufactured a bit low and they put a few "nips" in them with a pair of side cutters until it reaches a known value, like this:

(https://www.eevblog.com/forum/testgear/opening-a-testboy-tb-3000/?action=dlattach;attach=318422;image)

(sort of like laser trimming but without the lasers)

If it's a bit too high? Add a blob of solder!

Title: Re: Opening a Testboy TB-3000
Post by: Fungus on May 25, 2017, 10:20:18 am
Or... they might just have been cleaning their soldering iron.

Title: Re: Opening a Testboy TB-3000
Post by: WackyGerman on May 25, 2017, 11:38:39 am
Horrible build quality  :scared:. I am in doubt that the TÜV / CE certification is real . Scammer  :--
Title: Re: Opening a Testboy TB-3000
Post by: Huluvu on May 25, 2017, 02:48:43 pm
Same issue with my TB 3000 which I posted in 2013  :--

https://www.eevblog.com/forum/testgear/soar-multimeter/msg192944/#msg192944 (https://www.eevblog.com/forum/testgear/soar-multimeter/msg192944/#msg192944)
Title: Re: Opening a Testboy TB-3000
Post by: Hydrawerk on May 25, 2017, 04:59:54 pm
Is this a rebranded Mastech or something??
Title: Re: Opening a Testboy TB-3000
Post by: stj on May 25, 2017, 05:26:39 pm
Horrible build quality  :scared:. I am in doubt that the TÜV / CE certification is real . Scammer  :--

the certification is only done on a submitted device - the one they built carefully and de-fluxed first!!
Title: Re: Opening a Testboy TB-3000
Post by: PointyOintment on May 27, 2017, 05:27:54 am
Yeah, before I put it back together, I bent them apart and put some hotglue (forgive me) between the leads.

Careful with that. When you put glue on it, I think you have to worry about creepage distance, which is greater than the clearance requirement for a given voltage. With hot glue, though, you probably couldn't easily put on a blob that's too small.