Well I already have my first bad experience with Ali Express after 3 orders - Page 1
Forum section: electronics / beginners

author: JenniferG
author_rank: Frequent Contributor
timestamp: December 02, 2022, 02:33:19 pm
content: Received a 7 decade programmable resistor .. i.e. jumpers and SMD resistor series network.The resistors are placed on the board in reverse order. So if you set the 100k column to 1 you get 100 ohms instead of 100k, and vice versa. 10 Megaohm column is 0-9 ohms.

author: MikeK
author_rank: Super Contributor
timestamp: December 02, 2022, 03:57:01 pm
content: Sounds like desoldering/resoldering practice to me. You can have cheap or good, not both.

author: JenniferG
author_rank: Frequent Contributor
timestamp: December 02, 2022, 04:18:35 pm
content: Quote from: MikeK on December 02, 2022, 03:57:01 pmI guess it would be good SMD practice. I need to get a hot plate, hot air gun etc. Haven't done any SMD soldering. But plan to get into it. Would be desoldering and resoldering of 60 resistors, as well as seven 10 wide double row pin headers.

author: ledtester
author_rank: Super Contributor
timestamp: December 02, 2022, 04:41:57 pm
content: Does yours look like this?Can't you just cover up the incorrect headers with your own labels?

author: JenniferG
author_rank: Frequent Contributor
timestamp: December 02, 2022, 06:26:35 pm
content: Quote from: ledtester on December 02, 2022, 04:41:57 pmYeah I can. Still backwards and not typically how I look at base 10 number system but yeah it'd work.

author: JenniferG
author_rank: Frequent Contributor
timestamp: December 02, 2022, 06:29:34 pm
content: Wouldn't this device be great for programmable dummy loads for electronics projects? Each SMD is allegedly 1/2 watt, and many are in series.. so it can handle quit a bit of current I guess. More than enough for projects under 1A I think?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: December 02, 2022, 09:09:02 pm
content: To me this looks like a good opportunity to also test the refund process of Aliexpress, because this is clearly a faulty product.I also bought a few of these, but that was a few years ago, probably another batch and they work as expected.In the photo posted earlier you can also see that one is also ok.You can use your one as solder practice, but if you want to repair it, re-labeling, and possibly in combination with re-routing a few tracks seems an easier option.But considering the price of these things, just tossing it in the bin and getting a new one is also an option.Yet another option is to only remove the connectors and then add them from the other side.I've found that making labels in a spreadsheet works quite nice. You can set cell height to match 2.54mm and use the columns for alignment. After printing put transparent tape over it for longevity, then put it on your PCB and pre-punch the holes with a needle before inserting the pins. Some brands of tape do not like the heat of soldering irons and do weird things...

author: alm
author_rank: Super Contributor
timestamp: December 02, 2022, 09:31:54 pm
content: If you are sick of the bad assembly quality, what as far as I can tell is theoriginal design by Gerry Sweenyusing these headers and jumpers is still available fromTindie.Quote from: JenniferG on December 02, 2022, 06:29:34 pmAll resistors are in series. So all in series might be handle 30W (in theory given sufficient airflow), but the resistance will be 10.11111 MOhm, so you'd need a theoretical 17 kV to dissipate that 30W. At a more practical 5V / 1A, the resistance would have to be 5 Ohms, which would only involve 5 1/2 W resistors, for a maximum of 2.5 W. Never mind that the PCB probably doesn't have enough metal area to dissipate 2.5 W.

author: mikerj
author_rank: Super Contributor
timestamp: December 02, 2022, 09:48:13 pm
content: Quote from: JenniferG on December 02, 2022, 06:26:35 pmRotate the PCB and add labels for decade and the jumper positions as well, a set of sticky labels and an inket or laser printer would make a neat job . Puts the decades in the correct order and having zero at the bottom actually seems more natural to me at least. It's all a pain in the rear though, and you shouldn't have to do this stuff.

author: BillyO
author_rank: Super Contributor
timestamp: December 02, 2022, 11:47:56 pm
content: Speaking of resistance substitution boxes, I think I'm going to build something like this:Maybe add a 10M pot to it, but I've never really needed resistors over 100K very much.

author: ledtester
author_rank: Super Contributor
timestamp: December 03, 2022, 12:20:18 am
content: There's this old thread about using (the right kind of) thumbwheel switches:https://www.eevblog.com/forum/projects/diy-cheap-resistor-decade-substitution-box/msg56001/?topicseen#msg56001The 1-2-4-8 kind of thumbwheel switches can be used to make capacitor substitution boxes.

author: tautech
author_rank: Super Contributor
timestamp: December 03, 2022, 12:57:12 am
content: Quote from: JenniferG on December 02, 2022, 04:18:35 pmFor the majority of 2 terminal SMD you only need a K style tip with which you can bridge both pads and either sweep passives off or pick them with tweezers.Like this but you can find knock offs for lots less:https://hakkousa.com/products/soldering/soldering-tips/t35-03ku-knife-tip.htmlWouldn't be without a K style tip.

author: EPAIII
author_rank: Super Contributor
timestamp: December 03, 2022, 06:30:56 am
content: Frankly, the first time I saw the name, "Ali Express" I wasn't impressed.So far I see no reason to change that first impression.

author: radiolistener
author_rank: Super Contributor
timestamp: December 03, 2022, 10:38:07 am
content: I remember my first purchase on aliexpress and it was defectiveIt looks like not a good experience, but I made next purchases and they appears to be okay.Just keep in mind that some purchases can have issue, so don't forgot to record unboxing video and in case of issue you can attach it with video or picture which explains the issue. Usually aliexpress have fair decision.In order to avoid issue, just make sure that the seller has a lot of orders with a small percent of issue. Be careful if the seller has a new registration or has reputation below 4.6. I recommend to choose seller which already has a couple of completed orders for your product with a good feedback. Read feedback page for the product, it often has a photo, some extended info and sometimes you can find information about product issues.About 90% of orders on aliexpress are good. About 3% of issues can be quickly solved by seller in private communication even with no needs to involve aliexpress. About 1% is not solved at all, even with aliexpress team. And the rest 6% of issues are solved with help of aliexpress team, sometimes as partial refund and sometimes as full refund.Note, if you choose seller with a lot of already completed orders and good feedback it doesn't guarantee that your order will be ok, but in case of issue it will increase chance that your issue will be solved.

author: JenniferG
author_rank: Frequent Contributor
timestamp: December 03, 2022, 11:08:00 am
content: Quote from: Doctorandus_P on December 02, 2022, 09:09:02 pmWow, I got an email from Paypal just now:"ALIPAY US, INC. refunded $4.99 USD from your purchase on November 11, 2022."Seems as though they are good about refunding. There was an option for "return and refund" or "refund only". I selected "refund only" and showed a video with the problem. They obliged. I did ask for a $4.99 refund (they let you type the amount), but in the description of problem I mentioned I'd settle for $2.50 for the inconvenience since it was still usable. But they refunded me the full amount.

author: JenniferG
author_rank: Frequent Contributor
timestamp: December 03, 2022, 12:00:24 pm
content: Quote from: alm on December 02, 2022, 09:31:54 pmThank you for telling me about him, as I was wondering who created this. I watched his entire video. What a great guy.

author: JenniferG
author_rank: Frequent Contributor
timestamp: December 03, 2022, 09:17:30 pm
content: Printed a label with black background and white text on laser printer. Used double sided tape for the back and clear gloss for the front.I used black sharpie to color over the incorrect labels (black gaps in bottom of photo).EDIT: Excuse my hair in the photo! doh!

author: bidrohini
author_rank: Regular Contributor
timestamp: December 04, 2022, 06:59:15 am
content: I never really trusted this website. Sorry to hear about your mishap.

author: donlisms
author_rank: Frequent Contributor
timestamp: December 04, 2022, 07:19:12 am
content: Or... OR... !!! Take it as an opportunity to start getting used to the fact that the real-world implementation of a circuit is rarely very much like the conceptual representation of it!!!Needs labels, but there you go.

author: BeBuLamar
author_rank: Super Contributor
timestamp: December 04, 2022, 08:55:56 pm
content: But they gave the OP full refund. So the OP has the defective unit for free and could make it usable. So really is it bad?