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i won't buy chinise parts from aliexpress or ebay

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Koen:
12 years on Alibaba, about 10kEUR / year, zero issues, very happy overall. Just got my first bait and switch : https://www.eevblog.com/forum/manufacture/tewaycell-li-polymer-batteries-scam-bait-and-switch/

nigelwright7557:
Got 2 AD9220 a2d converters from Analogue Devices.
Bought 2 from Ali Express.
First pcb I used an AD device and got it working fine.
As an experiment I tried the Chinese device and couldnt get full speed out of it without lots of data noise.
I should know better by now than to risk Chinese parts.

Edward3121:
这样的元件并不适合在阿里巴巴(aliexpress)或者ebay上购买。因为这两个网站上的卖家鱼龙混杂。从这里买到的元件可能是“能工作”或者“可以用”的,但是长期使用或者用于极限情况时候会出问题;当然也会有很大几率买到不能用的器件。因为卖家为了利益,卖的元件是假冒的、翻新的、打磨的、甚至是工厂筛选下来的废料重新包装的。但是这不代表中国器件(chinise parts)是不行的,只是没买到好的而已。
提供一些建议(我自己的经验):
1.在阿里巴巴(aliexpress)或者ebay买元件(包括有源和无源器件),要有一定心理准备,因为可能有无法工作的。
2.经过自己尝试或者朋友推荐,确定一些比较可靠的卖家,尽量在这些卖家中买。
3.如果一定要在阿里巴巴(aliexpress)或者ebay买元件,而且是芯片类型的,不要相信所谓“全新”、“散新”、“原装”这样的字样,很多都是假冒的或者是翻新的。要买“原装拆机”的,也就是从旧的PCB上拆下的,没有经过其他处理的,这样能保证是真品。
4.建议去元器件零售商购买元件,比如贸泽电子、digikey、深圳立创商城(SZLCSC,中国)等等,价格会略高一些,但是能够保证品质。顺便说一下,深圳立创商城(SZLCSC)有很多中国产的(chinise parts)器件,质量也是有保障的,价格也很实惠。

VK3DRB:
A client commissioned a contract manufacturer in China to make a device I had been developing. Part of the device has two brand-name 100k 0.1% 0402 resistors used as a voltage divider from a precision 2.500V voltage source down to 1.250V used as a voltage reference. They built 100 prototypes of the boards, but there were about 10 failing boards with the same error in firmware - some failing straight away and others failing after a after a few weeks of testing. Found out the cause of the error: Some of the 100K resistors were out by up to 1%, with one measuring 97k... 3% low! The values were all over the shop.

The manufacturer's excuse was they might have had the temperature profile on their reflow oven set a little too high. I suspect this is complete and utter :bullshit: and it is more likely the manufacturer just had used cheapo generic resistors from the likes that you would see on eBay, AliExpress or a back alleyway behind the Shenzhen market for "a-dime-a-dozen". Even 1% resistors would not have that amount of variance from the same reel.  I have never seen resistors going low with too much heat. Going high with excess heat - maybe -  but there were no other issues on these boards that were quite complicated with many parts including BGAs.

SilverSolder:

--- Quote from: Quarlo Klobrigney on June 02, 2020, 02:11:54 pm ---[...]
Now how does one send a picture of completely missing goods. I'd like to know. :-//

--- End quote ---

Take a picture of your empty mailbox!   :-DD

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