Ebay 1% resistors off , now what ? - Page 1
Forum section: electronics / general

author: lordvader88
author_rank: Frequent Contributor
timestamp: July 16, 2019, 11:18:37 pm
content: On ebay I ordered a bunch of batchs of 50pcs 1W 1% metal film resistors. And not all off them are actually 1%. For instance in the 1k batch, some are 9701 ohm batch is mostly 0.89, one was 0.84, so that's technically way off.Never checked the rest yet. I will. I'm using a Brymen BM869s which is a GREAT DMM.So, they are not up to the standard they are sold as. What should I do. Should I complain to the seller who probably doesn't just sell's whatever they get ?Should I make a claim to Ebay for 'not as labelled ?I could record video of checking the values, but that would be a lot of extra hassle, since I don't have a cam, or any memcard to work with the phone I have that does video.What is the definition of counterfeit ? I'm going to inform the seller these are not all 1% resistors. Why not ?Of course I will absorb the ripoff, and never return anything to China, it costs me 15x the price to ship back.I have a 100% record with ebay, I should not tolerate junk parts.

author: Stray Electron
author_rank: Super Contributor
timestamp: July 16, 2019, 11:27:39 pm
content: I think that you answered your own question.PS Ebay/Pay Pal will make the seller pay for the return shipping on defective or not-as-described items. Sellers know that and very few ask for the parts back.

author: wilfred
author_rank: Super Contributor
timestamp: July 16, 2019, 11:42:06 pm
content: If you are going to buy components from some nondescript seller from China or anywhere where it is too costly to return them then just face the fact that you're going to get marginal results sometimes.Yes, you can file a claim and maybe you should maybe I would. If you've bought them from the type of sellers I buy from I doubt they'd have any idea what they are selling half the time. Their business is to empty a box and ship out little packages.I'm interested to know just how many are over 1% off tolerance and are they marked as 1%. I am expecting the variation in a batch to not spray around wildly. Are resistors tested before they are packaged in strips or reels or do entire batches get thrown off tolerance and hence sold off cheap on Ebay. I don't know. It's off topic I know.

author: mariush
author_rank: Super Contributor
timestamp: July 16, 2019, 11:42:59 pm
content: 970 ohm from a 1 kohm is a bit suspect. A 1000 ohm 5% tolerance resistor would be between 950 ohm and 1050 ohm ... if they binned the resistors and set aside the 990+..1010- to sell as 1% resistors, the 970 value would be right between 950 and 990 ...But I'd think a 5% resistor would be closer to the 990 ohm range.I would suggest double checking if your battery is charged to enough level, then measure the lead resistance and maybe zero it out before measuring, then maybe clean the leads of resistors a bit in case they're oxidized and try again.Also if you don't have an auto ranging meter, make sure you're using the right range to measure the resistors. Your multimeter will have something like 1-3% error +/- a few counts. So for example your meter may be off by 1% and -4 counts .. so a 1000 resistor may be measured as 990 ohm and then substract 4 count and it would show on screen 986 ohm if you're into let's say a 2000 ohm range.If it's the same, you either got 5% or 10% resistors... really the cheapest they could get.

author: John B
author_rank: Frequent Contributor
timestamp: July 17, 2019, 01:25:14 am
content: Just use them and don't buy them again. I've built tons of stuff with a variety of cheap ebay resistors, you just have to do more manual resistor selection if you need an accurate value. From memory, most of the 1/4W THT resistors I've purchased read lower than their rated value, and were around 300ppm tempco.Put in a bulk order from LCSC or something. Buy once, cry once. Some people will advise against stockpiling parts, but I think it's worth having a baseline inventory of most common resistor values, even if that means buying 100 of each. After that you can judge what values you consume the fastest.

author: excitedbox
author_rank: Regular Contributor
timestamp: July 17, 2019, 01:36:12 am
content: I just bought a sample book with over 4k resistors so even if they are off I have enough on hand to switch out for one that works.

author: lordvader88
author_rank: Frequent Contributor
timestamp: July 17, 2019, 04:25:05 pm
content: How easy is it to tell if they are just carbon film resistors painted blue ?

author: Tomorokoshi
author_rank: Super Contributor
timestamp: July 17, 2019, 04:55:41 pm
content: Select one and file it down lengthwise. Take a picture before each swipe. You can get to the internal construction, including the cap and the element. To hold it, solder it securely to a piece of perf board.

author: Kleinstein
author_rank: Super Contributor
timestamp: July 17, 2019, 05:28:49 pm
content: Carbon resistors tend to have a relative large positive TC (often > 300 ppm/K). Metal film resistors should usually be < 150 ppm/K.Another possible test would be measuring the resistor excess noise. This is usually much higher with carbon resistors. However this is not very easy. A usual way would be with a low noise amplifier (e.g. good OP wired as x 100) and than a way to record the data (could work with a good sound card or a DMM with fast (e.g. >= 5 SPS) reading towards the computer). 4 resistors in a bridge would be powered from something like a 9 V block.It is still possible to have poor quality metal film (thick film) resistors with noise similar to exceptionally good carbon film resistors.An easy way may be testing the way the resistors react to too much power and how they fail. This is supposedly different, but I have not done the test.Another chance could be accelerated aging: carbon resistors drift significant towards high resistance. So one could check how much the resistance changes in something like hours at something like 120-150% of nominal power.If all resistors tend to be low, there is a chance the meter is off a little and some of the error is from the meter.

author: Brutte
author_rank: Frequent Contributor
timestamp: July 17, 2019, 06:15:05 pm
content: My 1%eBaystory.

author: Johnny10
author_rank: Frequent Contributor
timestamp: July 17, 2019, 06:47:12 pm
content: My last 4 buys from China I received out of tolerance Capacitors, Resistors and marginally working IC's.However, I never had a problem getting my money refunded without sending items back.Usually within a few days of writing the company.It is never a good idea to send back to China, experiences with that just proved disastrous, long wait and lost articles, some of which came back to me months later as non-deliverable.Which also meant I never got money returned.My advice would be to talk to the company quickly.And start a return process through eBay.I rarely buy from China eBay anymore I have found that Arrow and other suppliers are quicker and have more guarantee of quality.Saves all the aggravation.

author: Cosmic Osmo
author_rank: Newbie
timestamp: July 17, 2019, 07:11:15 pm
content: There's no point telling the seller that their stuff isn't up to spec. They know already. If you complain to the seller, they will probably refund you without asking you to ship anything back. They want you to not open ebay complaints, because that gets them shut down eventually, so they'll just buy you off.

author: janoc
author_rank: Super Contributor
timestamp: July 17, 2019, 07:13:53 pm
content: For the record, if you are attempting to measure a 1resistor using that Brymen meter, you are going to have huge errors. The resistance of the probe wires, contact resistance (how are you probing that resistor? Just pushing it against the probe tips?) will easily cause 50-100% errors with such small resistances and, worse, the measurement will not be very repeatable.That Brymen 869 is a great meter but it doesn't have a four wire measurement option which is what you need for small resistors.And as far as those eBay resistors are concerned - you have got what you paid for. I have seen this with cheap resistors and capacitors as well, whether from eBay or AliExpress. If you actually need better than 5% accuracy for something then you are a fool to buy the cheapest parts on eBay, IMO. The resistors you have got were most likely some old stock or surplus/rejects with little/no quality control so finding that some are out of spec is not surprising. Other than that, I always check the value of the resistor before putting it in the circuit if it is something where the accurate value matters - even reputable vendors have tolerances and an occasional out of spec value (or I am a doofus and pick a wrong part!).

author: nctnico
author_rank: Super Contributor
timestamp: July 17, 2019, 07:47:28 pm
content: Penny wise, pound foolish if you ask me. I always buy A-brand 1% resistors and won't even touch the no-name brands from RS and Farnell. Solving a problem caused by a faulty resistor costs like 10,000 times the worth of the A-brand part even if you would earn the money flipping burners at McD. Even spare time is just too precious.I agree with John B: it is very handy to have a collection of common values on hand. Usually I start a collection of values with 1, 2.2 and 4.7 values in the range from 1 Ohm to 1M Ohm

author: floobydust
author_rank: Super Contributor
timestamp: July 17, 2019, 08:29:57 pm
content: What's happened is the brand-name through-hole resistors have all shrunk in size. The power dissipation ratings went up as size went down. A miracle of physics. Datasheet scrutiny and you will see they run hotter at 70-100C to get their power rating, smaller size and lower cost. It's just pushing the materials hotter. My last order of Stackpole 1/4W's ended up the size of 1/8W's.The chinese resistors with super thin leads and crappy paint are breadboard quality only.I ordered 1k 1% and got 100R 1%, and those measured around +/-5%. It was not the cheapest and from a store I've used before. Got a refund. They sell all the parts of the Bell curve.

author: John B
author_rank: Frequent Contributor
timestamp: July 17, 2019, 09:35:05 pm
content: Here's an example from yesterday: I was trying to build up an ebay-spec "LM2596" buck converter in a TO220-5 package. It's fake and total junk, it blew at around 1.5A output current. I had to sift through my resistors and my 27k "1%" ebay resistors do seem to be 1%....around a value of 26.3k. A 50V ceramic cap shorted at around 30V.It's a pretty typical story if you use stuff from ebay. Things just dont meet the specs that you expect them to.

author: thm_w
author_rank: Super Contributor
timestamp: July 17, 2019, 10:19:47 pm
content: Quote from: janoc on July 17, 2019, 07:13:53 pmYeah the lowest range of the 869 is 500.00 ohm 0.07% + 10d. So you could be 45% off on a 1 ohm resistor from the meter alone.Of course its probably not that bad, but best as you say to use a four wire measurement.

author: SparkyFX
author_rank: Frequent Contributor
timestamp: July 17, 2019, 11:10:01 pm
content: Quote from: floobydust on July 17, 2019, 08:29:57 pmWhich is why i wonder: are they marked after sorting? Where would be the point in testing, marking and then selling as a different tolerance? Did the test machine fail and the resistors therefore otherwise would have needed to be scrapped?I reckoned the specs of many mass produced parts are simply just the result of sorting whatever fell off the line, e.g. LED color and brightness.

author: lordvader88
author_rank: Frequent Contributor
timestamp: July 18, 2019, 05:50:32 am
content: Quote from: Kleinstein on July 17, 2019, 05:28:49 pmOk I haven't contacted the seller yet. I have a bunch of values from 1 guy, so I will have to test them. I have 3 DMM that i trust enough, thats not a concern, except for maybe the sub-1 ohm resistors, IDK, maybe my toys work fine at that too.I'm tempted to go over to the university for fun and to ask some hot girl scientist with access to some elemental analysis machine, to check themor maybe the police station would do it for fun, if they have nothing better to do(i would if i was a cop and had NBTD)maybe I should call the gov and ask who looks into counterfeit goods, and have the check some

author: Bassman59
author_rank: Super Contributor
timestamp: July 18, 2019, 07:16:30 pm
content: Quote from: lordvader88 on July 16, 2019, 11:18:37 pm... and you're surprised?

author: Brumby
author_rank: Unknown
timestamp: July 19, 2019, 04:23:18 am
content: Yes - I wouldn't be surprised, either.In fact, I grabbed a couple of packs a few years ago that were supposed to be 1% tolerance. When they arrived, I checked a few and found the variation from nominal was generally in the range of +0%, -2%. I still have them and use them. For many circuits you don't need tight tolerances and for those, these are perfectly suitable. The cost was almost insignificant, so I didn't bother complaining - besides, they were cheap enough for 2% resistors.In the OP's case, I would suggest to complain if you want. The seller is likely to refund, just to avoid bad feedback and/or a formal case being lodged against their account. If you get your money back and get to keep the product, then just file them away as 5% resistors and use them as such.

author: techman-001
author_rank: Frequent Contributor
timestamp: July 19, 2019, 01:14:38 pm
content: Quote from: Johnny10 on July 17, 2019, 06:47:12 pmI agree 100%, arrow.com are excellent. Keep a eye on their 'overstock' category and one can get excellent prices.I only buy from China now as a last resort because I've been ripped off too many times with utter junk unfit for purpose.

author: lordvader88
author_rank: Frequent Contributor
timestamp: July 20, 2019, 05:24:48 am
content: Quote from: Bassman59 on July 18, 2019, 07:16:30 pmI guess not now. The last big batch of 1% 1/4W resistors was also off. Again I really should have complained at the time.

author: Brutte
author_rank: Frequent Contributor
timestamp: July 20, 2019, 05:02:59 pm
content: Quote from: lordvader88 on July 20, 2019, 05:24:48 amI have taped a pair of 1.06 ratio resistors on the top of the package and sent the whole batch back to HK.I did receive a refund of $12 and because of that I decided not to leave any feedback although this was evidently a lie with the 1% tolerance.

author: floobydust
author_rank: Super Contributor
timestamp: July 21, 2019, 02:58:59 am
content: Quote from: techman-001 on July 19, 2019, 01:14:38 pmIt's not the distributor, it's the manufacturer of the resistors. I find name brands from Taiwan and Japan are great for quality.china's low quality stuff, there's no savings or deal once you include troubleshooting time or the email crap to get a refund.

author: KrudyZ
author_rank: Frequent Contributor
timestamp: July 21, 2019, 09:25:38 am
content: I always assumed that the ebay offers for 1% resistors meant that 1% of them are usable

author: techman-001
author_rank: Frequent Contributor
timestamp: July 21, 2019, 09:38:29 am
content: Quote from: floobydust on July 21, 2019, 02:58:59 amGood point

author: OwO
author_rank: Super Contributor
timestamp: July 21, 2019, 10:58:04 am
content: First, stop buying from ebay. If you really must get cheap parts aliexpress is a bit better and has a functional dispute system where the seller can not "stall" you (because once you start a dispute if the "timeout" is up the dispute is resolved in your favor). SMD passives are the last thing I would buy on ebay/aliexpress though, because you can get them for similar prices on LCSC. The comment about manufacturer vs distributor is bollocks because no proper manufacturer can sell 5% resistors as 1% and expect to stay in business. It's always an ebay seller buying 5% resistors and selling them as 1%, simple as that.

author: bd139
author_rank: Super Contributor
timestamp: July 21, 2019, 11:04:11 am
content: Even better, go here and bag a whole set of E12 resistors from the ones marked as "Royal Ohm". They are decent resistors:https://www.taydaelectronics.com/resistors/1-4w-metal-film-resistors/test-group-2.htmlE12 = 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82Buy 10 each of all values apart from the 10, 22, 47 of which buy 30 each.Any that aren't Royal Ohm, just skip them.I basically bought their sample book and top up from CPC here in the UK who's "multicomp" resistors are made by Royal Ohm.

author: SilverSolder
author_rank: Super Contributor
timestamp: July 21, 2019, 12:53:43 pm
content: Quote from: OwO on July 21, 2019, 10:58:04 amIsn't that exactly how eBay's dispute system works?

author: NorthGuy
author_rank: Super Contributor
timestamp: July 21, 2019, 01:02:59 pm
content: Quote from: nctnico on July 17, 2019, 07:47:28 pmI still have a full assortment of TH resistors from 10 Ohm to 33 M, mine are mostly 5% though. They're mostly useless now, but I still use them in breadboards.1% 1 Ohm TH resistor is a joke - there's lead resistance, PCB trace resistance, component lead resistance - you'll never get the combined resistance to 1%. In many cases, you may consider 4-lead resistor to eliminate all these factors. And I don't think it's that easy to even measure 1 Ohm resistor.If you bought something on eBay and it's not usable, just throw it into a garbage can and claim the refund.Resistors on DigiKey are cheap too, and you get free shipping on orders over $100, and you receive it next day.

author: Beamin
author_rank: Super Contributor
timestamp: July 21, 2019, 01:15:54 pm
content: I don't understand why if you want precision or quality or 1% why someone would buy from ebay china. My experience is more then 50% of the stuff is broken or majorly defective but 1/5th the price so ordering two and you are still ahead but not after waiting for a month.Some sellers will try and not refund you the whole price on a two dollar item. Unbelievable to put that much fight into a few cents.

author: techman-001
author_rank: Frequent Contributor
timestamp: July 21, 2019, 09:54:35 pm
content: Quote from: OwO on July 21, 2019, 10:58:04 amThen things must have changed in the last few years because I was stalled out of a "never received" dispute on Aliexpress in my last Chinese electronics purchase (only a few $) but I have never had a unresolved dispute with Ebay. I'm in Australia and I do understand that shipping within China is very advanced, reliable and a totally different matter to shipping *outside* China.Nowadays I avoid Aliexpress altogether, I avoid Ebay when I can, and buy from reputable sellers such as arrow.com or mouser.com etc because my time is infinitely more valuable than cheap parts that don't arrive, take 30+ days in transit, are fake, or just don't work.

author: NorthGuy
author_rank: Super Contributor
timestamp: July 21, 2019, 11:28:41 pm
content: Quote from: techman-001 on July 21, 2019, 09:54:35 pmI always receive what I ordered on Aliexpress. Although it may take much longer than expected, but it always arrives. However, these things are always defective or non-functional. I don't try very often, but I keep trying. May be it's just my bad luck or inability to tell a good seller from bad.It's much better on eBay - 90% of what I buy works.