Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

The mind boggles...

After all the effort you'd have to go to to either remove clean and relabel old chips, or idk, relabel faulty ones (can you even buy those from manufacturers? Why would they sell something like that?), there can't be a huge margin in it.

Surely it would be easier to just resell genuine ones.   

EDIT: I meant to specify doing this for jelly-bean logic like the hc595's that bd mentioned. I can see there'd be a bigger margin on more specialised chips.

   Nope. This is for SURE "a thing".

When I was fixing The Dark Lord Regza I bought a number of oddball regulator ICs from China, because buying them anywhere else would have made the BOM far more than a 42" 1080i TV was worth. All but one order (which of course, was NOT needed  ) were very obviously "cleaned-up" used pulls; in most cases poorly cleaned up, with clipped crooked leads and little spots of thermal paste still present. There was no evidence that they had been relabeled in any way, however. I took pictures of some of them at the time, intending to lambaste the sellers in here; but once I had the old beast finally off the bench after round 3, I couldn't find them. Two of the ICs actually worked and are powering the TV right now (knocks on the SoW for continued good luck).

This is very clearly one of those "cottage industries" which has sprung up as a byproduct of American-style "culture of wastefulness"; I'm pretty sure it's well-known in the "badcaps forums" subculture and is something eBay (and Amazon, BTW) "just doesn't talk aboot".  I mean, you see a $27 IC for sale at 2/$12 delivered, even via "slow boat from China", you have to know something's up. 

IMO, it's probably the reason they're usually offered in multiples; to appeal to those who buy them knowing they're taking a chance but "there IS a backup part". Also, there's a certain level of "playing the odds" on both sides here; while the buyer is obviously taking a risk, the seller is taking a risk whether the buyer can be arsed to file a claim.  My guess is that for a lot of people (me included, in one case) unless the parts just never arrive that's going to be a "NO."

All the horrible health side-effects of doing something like this for a living set aside; I have to applaud these individuals their resourcefulness, while at the same time feeling some shame for supporting the slave economy which makes this seem like a way out of "the life" for them. 

I see it this way... all those years we were dumping our e-waste on them by the boatload for a pittance; now they're selling it back to us by the gram, just like the corner coke dealer.

mnem

[mnementh]

So I don't really follow the TEA thread anymore since it blew up to the point that there are 20 pages to catch up on if I don't drop in for a couple days.  But I thought I'd drop back in to see if people here are aware of the existence of...

Nixie Tube Masking Tape:

   Found at https://kadenken.com/view/item/000000000894 by someone on Twitter.

Well, now that's fun. Looks like Cubdriver and nixiefreqq have to stock up.

wow.  it IS possible to hate something, and at the same time want it. (is that cognitive dissonance or is there a better term to describe it?)

Yes... a "hate fuck".

mnem
Don't knock it 'til you've tried it.

[AVGresponding]

That's exactly my point.

$27 chips at $6 each, you can see the margin is big if the chips are costing them a few cents each maximum, but jelly-bean logic chips are only a few cents each new anyway, so there's no visible margin.

The ones bd mentioned, 74HC595, can be had even in modest quantities for around $0.20 each, so you'd have to scam a crap-ton of people to make a worthwhile profit there.


The weird drifty behaviour of that 4503 has me scratching my head and shrugging my shoulders. I know Specmaster has cleaned the board thoroughly; he had to as the old memory battery had shit all over it.
Normally when you get odd behaviour on the ohms range it's something like the movs have been tickled and they're out of spec, but he's checked that too, so iono   

[mnementh]

It's FINALLY Here!!!       After WEEKS of anticipation... I can now present to you: THE STICK OF WISDOM!

Congrats, mnem! What are ya gonna first?

TBH, I'm still in the "fondling" stage with it...

mnem
 

[bd139]

That's exactly my point.

$27 chips at $6 each, you can see the margin is big if the chips are costing them a few cents each maximum, but jelly-bean logic chips are only a few cents each new anyway, so there's no visible margin.

The ones bd mentioned, 74HC595, can be had even in modest quantities for around $0.20 each, so you'd have to scam a crap-ton of people to make a worthwhile profit there.


The weird drifty behaviour of that 4503 has me scratching my head and shrugging my shoulders. I know Specmaster has cleaned the board thoroughly; he had to as the old memory battery had shit all over it.
Normally when you get odd behaviour on the ohms range it's something like the movs have been tickled and they're out of spec, but he's checked that too, so iono   

I think it's a case of someone goes to a crap market in Shenzhen to stock up on 595's for their aliexpress / ebay store and hits the lowest bidder. The lowest bidder is a guy with a crate of rejected parts and has relabelled them. The buyer doesn't give a fuck as they look the part, he's got 20 different store fronts, 80% of people don't complain or just chuck it away or doesn't know if it works or not either way so he's up money even if he sells 50k shite parts.  .

"Statistical capitalism" at it's best.

Actually I should write a Medium post or some old shit on statistical capitalism as I just invented that phrase 

Edit: also the resellers don't know what the fuck they are selling most of the time. In with your NanoVNAs are sex toys, dog uniforms, ICs, kitchen gadgets that cut your fingers off, death lasers, all sorts.

[mnementh]

@AVG: Yeah, I guess I could have phrased it differently; I was meaning to reinforce your statement from the other side of the argument.

I guess the simplest test for intermittently leaky MOVs would be to remove them entirely and observe over time to see if the drift goes away, right?



@bd: I dunno; doesn't this phenomenon all fall under the umbrella of the Greater Internet Fuckwad Theory...?

mnem
 

[Cerebus]

"Statistical capitalism" at it's best.

Actually I should write a Medium post or some old shit on statistical capitalism as I just invented that phrase 

Yeah, but call it Stochastic Capitalism for the added buzzword factor.

Edit: also the resellers don't know what the fuck they are selling most of the time. In with your NanoVNAs are sex toys, dog uniforms, ICs, kitchen gadgets that cut your fingers off, death lasers, all sorts.

Too true. That DAC board I bought a few weeks back came from just such a seller - they even included a little 'free gift' teddy bear with it:



(Quite cute actually).

So when I had a problem with it I didn't have much hope of getting a sensible reply but I went ahead and contacted them anyway (with full technical details). I was roundly surprised when I got the reply in Chinglish that, once appropriately translated, boiled down to "The DC-DC converter part on this has rather high inrush current; up the current limit on you bench supply and it'll work fine".

[AVGresponding]

I guess the NanoVNA sex toys make them enough profits that they don't care about the hit they take on a few thousand cheap-assed-chips   

[Specmaster]

@AVGresponding Could I please ask you if you'd be so kind as to measure the voltages on pin 26 and pin 32 of your MAX134 for me please? I'm getting 1.227V on pin 32 and pin 26 gives 670mV.

[Specmaster]

That's exactly my point.

$27 chips at $6 each, you can see the margin is big if the chips are costing them a few cents each maximum, but jelly-bean logic chips are only a few cents each new anyway, so there's no visible margin.

The ones bd mentioned, 74HC595, can be had even in modest quantities for around $0.20 each, so you'd have to scam a crap-ton of people to make a worthwhile profit there.


The weird drifty behaviour of that 4503 has me scratching my head and shrugging my shoulders. I know Specmaster has cleaned the board thoroughly; he had to as the old memory battery had shit all over it.
Normally when you get odd behaviour on the ohms range it's something like the movs have been tickled and they're out of spec, but he's checked that too, so iono   

I think it's a case of someone goes to a crap market in Shenzhen to stock up on 595's for their aliexpress / ebay store and hits the lowest bidder. The lowest bidder is a guy with a crate of rejected parts and has relabelled them. The buyer doesn't give a fuck as they look the part, he's got 20 different store fronts, 80% of people don't complain or just chuck it away or doesn't know if it works or not either way so he's up money even if he sells 50k shite parts.  .

"Statistical capitalism" at it's best.

Actually I should write a Medium post or some old shit on statistical capitalism as I just invented that phrase 

Edit: also the resellers don't know what the fuck they are selling most of the time. In with your NanoVNAs are sex toys, dog uniforms, ICs, kitchen gadgets that cut your fingers off, death lasers, all sorts.

Yep, that sounds just about right to me, it never ceases to amaze me just some these sellers actually stock and sell, especially those on eBay. If they can get something cheap, that they believe will sell for loads more than there'll buy it, I'm sure that is how it works.

That being said though, the Chinese seller that I brought the duff chip from only lists electronic components on his eBay shop so you would think that he does at least understand what he's doing. Interestingly he claims on his shop that the MAX134's are used but tested for functionality. The photo he has for that shows the white printing but all the wrong fonts and locations. The German seller shows what I believe to be a genuine one as everything matches the one in the meter and is more in line the makers prices.

[Specmaster]

"Statistical capitalism" at it's best.

Actually I should write a Medium post or some old shit on statistical capitalism as I just invented that phrase 

Yeah, but call it Stochastic Capitalism for the added buzzword factor.

Edit: also the resellers don't know what the fuck they are selling most of the time. In with your NanoVNAs are sex toys, dog uniforms, ICs, kitchen gadgets that cut your fingers off, death lasers, all sorts.

Too true. That DAC board I bought a few weeks back came from just such a seller - they even included a little 'free gift' teddy bear with it:

[ Attachment Invalid Or Does Not Exist ]

(Quite cute actually).

So when I had a problem with it I didn't have much hope of getting a sensible reply but I went ahead and contacted them anyway (with full technical details). I was roundly surprised when I got the reply in Chinglish that, once appropriately translated, boiled down to "The DC-DC converter part on this has rather high inrush current; up the current limit on you bench supply and it'll work fine".

So, did it work after you upped the current limit???

[BU508A]

Yep, that sounds just about right to me, it never ceases to amaze me just some these sellers actually stock and sell, especially those on eBay. If they can get something cheap, that they believe will sell for loads more than there'll buy it, I'm sure that is how it works.

That being said though, the Chinese seller that I brought the duff chip from only lists electronic components on his eBay shop so you would think that he does at least understand what he's doing. Interestingly he claims on his shop that the MAX134's are used but tested for functionality. The photo he has for that shows the white printing but all the wrong fonts and locations. The German seller shows what I believe to be a genuine one as everything matches the one in the meter and is more in line the makers prices.

If you have bought the MAX134 here from this seller , then I think you have bought a geniuine one. I've bought myself occasionly parts from Kessler electronic and was always satisifed with what I got. I can recommend this seller (no affiliations besides being a happy customer).

[Specmaster]

Fingers crossed on round two. Does the print rub off the original replacement? 

One thing I tend to do with ICs is apply power to the supposed power pins and see what happens. I had some fake hc595's and when you connected the power they got hot  (inputs were not floating btw)

I can't get the print to rub off but the print is nothing like that of the original or that of the one coming from Germany, so it could well be a fake. The print on the Chinese one is laser etched I think. One thing I did notice when I switched it on prior to swapping the chip was that readings were way off again, something like (depending on which range) 200 to 500mV from the correct figure. Today, I looked at it again but checked the mem retention battery voltage and it was reading 2.65V which was correct, rising 2.7 after switch on to keep the battery topped up, so  , why would the reading against a known standard change? Did a quick calibration of DCV and it is now reading correct again???

Yeah that's dodgy as hell. They usually have it white printed on it.

It might be something external to the ADC. You'd have to pin the ADC input at full scale with a voltage reference + divider and work out what the deal is. It It might even be a dirty board. The high impedance points need to be super clean i.e. scrubbed with isopropyl.

I scrubbed it again, all over on both sides with 99% isopropyl, 3 times and let it dry. So far I have not noticed anything different, re-caled the DCV lower ranges and it reads fine now, the acid test will be if it still reads the same in a few days time after I leave it to stand without powering it up. I have tested the MOV's with a meter capable of reading up to 60M and they read as if they are open circuit, both individually and with all three in series, so they do appear to be fine. So they are not the cause of the the ohms range on auto or manual max, reading 10M instead of O/R.

[Specmaster]

Yep, that sounds just about right to me, it never ceases to amaze me just some these sellers actually stock and sell, especially those on eBay. If they can get something cheap, that they believe will sell for loads more than there'll buy it, I'm sure that is how it works.

That being said though, the Chinese seller that I brought the duff chip from only lists electronic components on his eBay shop so you would think that he does at least understand what he's doing. Interestingly he claims on his shop that the MAX134's are used but tested for functionality. The photo he has for that shows the white printing but all the wrong fonts and locations. The German seller shows what I believe to be a genuine one as everything matches the one in the meter and is more in line the makers prices.

If you have bought the MAX134 here from this seller , then I think you have bought a geniuine one. I've bought myself occasionly parts from Kessler electronic and was always satisifed with what I got. I can recommend this seller (no affiliations besides being a happy customer).

Yes, that's the seller the second one is coming from. At this stage I'm not 100% certain if the one I have is faulty or not, if it turns out that it's ok then the price paid for the chip is worth it in my view as it better to swap it out and check. If need be I can always relist it.

[Cerebus]

So, did it work after you upped the current limit???

Oh, yeah they were bang on. The point was more the unexpected technical comprehension from a seller of Sexy Santa outfits, teddy bears, 16-bit DAC evaluation boards and butt plugs.

[nfmax]

So, did it work after you upped the current limit???

Oh, yeah they were bang on. The point was more the unexpected technical comprehension from a seller of Sexy Santa outfits, teddy bears, 16-bit DAC evaluation boards and butt plugs.

They are probably all represented by the same Chinese characters

[Specmaster]

So, did it work after you upped the current limit???

Oh, yeah they were bang on. The point was more the unexpected technical comprehension from a seller of Sexy Santa outfits, teddy bears, 16-bit DAC evaluation boards and butt plugs.

Well if nothing else, it did prove that you can't always judge a book its cover, or in this a seller by his product portfolio   

[Ice-Tea]

So, did it work after you upped the current limit???

Oh, yeah they were bang on. The point was more the unexpected technical comprehension from a seller of Sexy Santa outfits, teddy bears, 16-bit DAC evaluation boards and butt plugs.

Do they offer combined shipping discounts?

[Cerebus]

So, did it work after you upped the current limit???

Oh, yeah they were bang on. The point was more the unexpected technical comprehension from a seller of Sexy Santa outfits, teddy bears, 16-bit DAC evaluation boards and butt plugs.

They are probably all represented by the same Chinese characters

Hee hee. You go to buy a DAC board and you just let your voice drop on one of the syllables and you get the "Liver Disturber with !!Free Lube!!" instead...

[nfmax]

Many years ago I heard a talk given by one of the Bletchley Park cryptanalysts, who had been on the first "learn spoken and written Japanese in 6 months" crash course. He described how a Chinese dictionary is organised - apparently there are symbol 'roots' that can be recognised, and the dictionary is organised by root.

[tggzzz]

When looking up "trouble", which comes first - the "roof" or "two women"?

Supposedly the Chinese ideogram for trouble is "two women under one roof". I really don't care whether or not that is actually the case, and will ignore any efforts to convince me otherwise.

[nfmax]

I learned the other day, courtesy of the historian Tom Holland's Twitter account, that the Latin verb instruo can mean both "I deploy troops in battle order" and "I provide a gift to the happy couple from their wedding list"

[Saskia]

Update from the power supply front: Seller wants to have the defective PS back and refund my money, stating that I should have filed a claim with ebay and that his packaging was sufficient and that it was cheap in the first place.

What would you do ? keep that thing (grudgingly) or send it back in his shoddy packaging ?

[bd139]

I'd file a claim with paypal. No excuse. Seller sounds like a prick.

[Ice-Tea]

Update from the power supply front: Seller wants to have the defective PS back and refund my money, stating that I should have filed a claim with ebay and that his packaging was sufficient and that it was cheap in the first place.

What would you do ? keep that thing (grudgingly) or send it back in his shoddy packaging ?

Separate reason from passion. Do you want it for the price you payed for it? Keep it, case closed. Not worth it? Return it.