One more mind-bogglingly absurd example. it is known JLCPCB send an e-mail every time a new order goes into production and, days later, another one to notify that it has been shipped. We assume that this is an automatic process in which a server sends an e-mail once the order changes to that status, so how is it possible that for one of my orders, I never received the e-mail when it went into production but I did when it was shipped? Some will think that it was my anti-spam filter or my spam box (which do not exist), failures in my mail service provider,... in short that it was my fault. I won't go into details but suffice it to say that in my case it is more likely that one day the sun won't rise than one of my e-mails will be lost. At the time I was surprised but given the continuous disappointments with the Live chat and the support service, I assumed that it was not important, that sooner or later the progress of the order would continue and that it was not worth contacting to ask what had happened. Is this a serious issue? No. Is it an important issue? No. Just another drop in their ocean of issues.
Oh dear, oh dear, oh dear. SMTP email is NOT an infallible process. I've been sys-admining SMTP mail for well over 1/4 of a century. Speaking as a
genuine domain expert I can say that your claim "
I won't go into details but suffice it to say that in my case it is more likely that one day the sun won't rise than one of my e-mails will be lost." is utter bull. I'm sorry for being blunt to the point of rudeness but I've had my fill of Dunning-Kruger cases today and I can say with absolute certainty that someone who would make the assertion you have does not know what they are talking about, in fact does not know how email works because so much of the process is out of control of the receiving party that no knowledge person would make that claim.
On the other hand I don't know why the recurring fallacy of the "too cheap" price comes up again and again. Anyone could say, "you paid 'only' N dollars? then what are you complaining about?" but, unfortunately, the world doesn't work that way - how much would you have to pay to have the right to complain? There is an implicit and explicit contract between supplier and customer, even more after years ordering, and price and quality minimums are included in the agreement. I understand that someone does not like those prices and always has the freedom to opt for other manufacturers but that does not imply that paid a price, the customer has no rights. By the way, including all the extra costs I am paying around $20 per order (for each order in a batch), sometimes more, and shipping costs around $30 and $40 (depending on the number of orders in each batch); not just the $2 or $4 offers.
I constantly find myself amazed that JLCPCB can charge what they do and still make some money on the deal. Moreover they turn out decent boards for that price. Go and get yourself a quote from a European or American board house before you start talking about prices. $20 for an order? So what! That's peanuts. That wouldn't even pay for a single 160x100mm eurocard board from an EU/US board house. Basic JLCPCB 2 layer board, 100 x 160mm, 10 off = $17.50. Same order, same capabilities as the JLCPCB process = $232.78 from eurocircuits. Get real, you're getting a
bargain for your $20.
You must have heard the statement "You pays your money and you takes your choice". By choosing to pay as little as JLC ask you're implicitly accepting that you're getting "cheap and cheerful" service. If you expect top of the line service, from a top of the line board house you will have to pay for that, and you will pay considerably more than you do with JLC. The $20 you pay to have a set of boards
custom manufactured for you, with two silkscreens, two solder masks, and through plated holes would not even buy you a pub lunch in London. I suspect it wouldn't buy you the equivalent meal in Tokyo either.
If you read and interpret their capabilities statements correctly (which frankly
can be a bit vague at times and looks like it has suffered a bit in the chinglish department), set those capabilities properly for your board and deal with any DRC issues your boards will sail through JLCPCB. I've pushed 2 and 4 layer boards with 0.5mm pitch ICs on through JLCPCB and have received acceptable results every single time, and I'm a fussy, demanding bastard when it comes to quality. If they pass my informal quality standards (I don't do incoming inspection of them with my Mitutoyo metrology equipment, but I could if I wanted to) then I suspect that they are good enough for anybody. Yes, the slikscreen on the 2 layer prototype process could be better, but on the 4 layer process the silkscreen has been faultless, soldermask pristine, and I really can't see what I'd get better by paying a lot more elsewhere.
The only problem I ever had was on one 2 layer prototype order for 5 boards where they came back "Sorry there is a fault on one board and we don't think it's good enough to send out. OK if we credit you for this board?". So I got a $2 credit on a $2.50 (plus postage) order for accepting 4 boards instead of 5.