What I just received from ebay today... "Working Fluke 179" - Page 1
Forum section: electronics / testgear

author: windsmurf
author_rank: Frequent Contributor
timestamp: April 10, 2019, 10:25:15 pm
content: I'm returning this one... thought I'd share before I send it back on its way...Anyone know what causes something like this? What are those components that are fried? Looks like there was a mini explosion....

author: joeqsmith
author_rank: Super Contributor
timestamp: April 10, 2019, 11:35:35 pm
content: There have been a few members on this site that have posted pictures of their jumped fuses. I watched a video not too long ago where a guy had replaced theirs with something from the local hardware store.

author: NoisyBoy
author_rank: Frequent Contributor
timestamp: April 11, 2019, 03:19:43 am
content: It is unfortunate that there are so many shady seller on eBay, they probably figure you will never open the meter to look inside.eBay and Paypal are pretty good with protecting buyers, I hope they can get this sorted out for you.

author: windsmurf
author_rank: Frequent Contributor
timestamp: April 11, 2019, 06:34:00 am
content: Quote from: NoisyBoy on April 11, 2019, 03:19:43 amThe surprising thing is, this meter actually worked (already sent back), at least for the low dc milliamps measurements I did with it in both the 400mA and the 10A inputs. I was surprised it works with the insides fried like that... so I'm assuming those parts are part of input protection and not needed for measurement? Or maybe its for AC input... Don't know much about the amps input protection other than the fuses. The installed fuses were good.So the seller may have not known about it... maybe he is a pawn broker and his cursory tests seemed good...His listing had 30 days money back, so EBay allowed me to easily start the return process.

author: Noy
author_rank: Frequent Contributor
timestamp: April 11, 2019, 06:41:02 am
content: Looks Like a TVS Diode or Varistor, Transorb after a Bridge rectifier..Protection against high voltage Spikes... But this was one with a Lot of Energy... Big Surge or Lightning Strike..

author: Fungus
author_rank: Super Contributor
timestamp: April 11, 2019, 06:53:55 am
content: Quote from: windsmurf on April 11, 2019, 06:34:00 amYep.Looks like a clamping diode to me. meter will still measure without it (it must have died open-circuit).

author: rsjsouza
author_rank: Super Contributor
timestamp: April 11, 2019, 05:32:34 pm
content: The first photo gives me the impression a spark jumped from the resistor lead to the PCB track of the Diode. If so, it may have been quite the overvoltage (I don't have my 179 anymore to actually figure out what circuit branches these two parts belong).

author: stj
author_rank: Super Contributor
timestamp: April 12, 2019, 11:10:05 am
content: it's sad to see that got sold, it would be so easy to clean that up and replace the parts first before selling it.

author: Fungus
author_rank: Super Contributor
timestamp: April 12, 2019, 11:15:53 am
content: Quote from: stj on April 12, 2019, 11:10:05 amI'd prefer to know if something like that had happened to a meter, not have somebody clean it up and sell it on.

author: Electro Detective
author_rank: Super Contributor
timestamp: April 14, 2019, 12:49:12 am
content: Quote from: Fungus on April 12, 2019, 11:15:53 amor the seller post pictures of the barbequed insides, as well as the meter 'working'and auctioned 'as is' so whatever price people think it's worth to them, to bid/buy/offerresulting in a good Ebay Feedback thing happening both ways...or is that too simple, honest, passe and uncool in 2019?

author: james_s
author_rank: Super Contributor
timestamp: April 14, 2019, 04:29:02 am
content: That bridge rectifier is cratered too. I'd say 50% chance that the seller didn't know there was anything wrong with the meter. There are quite a few sellers that have stuff like this that they don't really know anything about, if they test it at all they turn it on and it looks like it does something so they assume it works, for the occasional item like this the refund when it turns out to be defective is a cost of doing business. I would guess that a majority of sellers are not going to take the back off to look inside a piece of gear.

author: HKJ
author_rank: Super Contributor
timestamp: April 14, 2019, 06:16:11 am
content: I looks like the mA overload protection, the bridge and diode protect the shunt resistor until the fuse blows.I wrote a bit about multimeter input protection here:https://lygte-info.dk/info/DMMDesignProtection%20UK.html

author: Chris56000
author_rank: Frequent Contributor
timestamp: April 14, 2019, 09:08:33 am
content: Hi!That little lot isn't too much of a problem to fix, I think the diode is a "DH240" SMB case TVS, whilst the bridge is DF08, and you should be able to get rid of the splat–marks with IPA and a fibre pen!!Chris Williams

author: Electro Detective
author_rank: Super Contributor
timestamp: April 14, 2019, 10:09:17 am
content: Quote from: james_s on April 14, 2019, 04:29:02 amAgreed, but surely an internal barbeque like that would emit some ongoing magic smoke 'fragrance' to the seller?The smell test is one of my main inspection methods, way before I consider a 'buyer beware' purchase gamble.Sigh...it's Ebay, either the good sellers and their stuff are too far away (or freakin paypal only BS)and the suss sellers with the claimed 'working' gear are close by, and accept all methods of payment.Sometimes I do get lucky,though not as many times as I would like...and let's not forget those last few seconds bid snipers

author: james_s
author_rank: Super Contributor
timestamp: April 14, 2019, 06:32:20 pm
content: Admittedly it has never even occurred to me to smell gear, but then my sense of smell is not very good anyway.Snipers used to annoy me, but then I figured if you can't beat 'em, join 'em. Anything that I'm bidding on I use a sniping service, always, have for years. Bidding early just invites bidding wars and drives up the price, sniping manually is a waste of time. I put the max I'm willing to pay into the sniper and it fires off a second or two before the listing ends. The only time I don't snipe is when I don't really care if I get something or not and just toss in a lowball bid on that offchance that nobody else bids.

author: Fungus
author_rank: Super Contributor
timestamp: April 14, 2019, 07:38:50 pm
content: Yep. There's no point in using eBay any other way. Lowball if there's no other bids, snipe if you're really after something.

author: testpoint1
author_rank: Frequent Contributor
timestamp: April 15, 2019, 03:23:15 pm
content: use the mA gear to test the high voltage may cause this, normal PCB should be: