ebay'ers ruining gear by being stupid - Page 1
Forum section: electronics / general

author: linux-works
author_rank: Super Contributor
timestamp: February 17, 2018, 04:34:50 am
content: sigh. this really bugs me.I love old HP calculators. the era of the woodstock (the hp25 and its peers) had no equal before or after, by any vendor.I go to ebay looking for these things every so often and I regularly see IDIOTS who clearly have no battery pack or an old bad 'open circuit' one and yet they ignorantly plug in the adapter (which puts UNFILTERED ripple DC on the bus) and if there's no batteries to smooth it out (part of the design, stupid as it was by HP) then you just ruined your irreplaceable calc ;(so often I see "well, I plugged it in, I see some light, but it does not seem to work when I press buttons". yeah, you may have had a working calc that would be worth $150, but now its scrap, nearly worthless other than the plastic itself.does this kind of thing bug you guys, too?idiots on ebay who know nothing, care nothing and do zero research (the derog term is 'flipper') and keep ruining things or misrepresenting things. really annoys me. the supply of old used HP25 calcs (etc) isn't getting bigger; and the clueless out there are helping to reduce the # of working models in the world.(sigh)

author: daybyter
author_rank: Frequent Contributor
timestamp: February 17, 2018, 04:40:29 am
content: I like old ti calculators. Ti 57,58c,59 and such. Same here. Had to pass offers, because the seller ran it with no battery. And some even dump the battery pack, because they think it is dead anyway. So you cannot just replace the cells to revive it.

author: Brumby
author_rank: Unknown
timestamp: February 17, 2018, 05:25:28 am
content: I first encountered HP calculators with the HP45 - somebody else's. That was a very cool design. Very appealing. Then I saw the HP65 - again, somebody else's - and that was just mind blowing.So was the price.By the time my funds and prices got close, I was able to get the HP25. Nowhere near as sexy as the 45, but it did have programming. Unlike the 65 though, there was no way to store "programs".I have no ideawheremy HP25 is these days...

author: linux-works
author_rank: Super Contributor
timestamp: February 17, 2018, 05:34:28 am
content: I have an hp41 that someone just GAVE me, long time ago, before ebay days. all I had to do was rewire the lcd display using wire-wrap since the contacts were bad and that's why it was given to me. a bit of work and its no longer 'original' inside but it WORKS and I didn't ruin its function at all.but I still prefer the hp25 (just got an hp21 which has its own charm). the way it fits into your hand, its amazing. that level of design is long gone. no one thinks to that level when they make consumer products. the FEEL of that calc in your hand while you hit buttons with fingers on the same hand or other hand. marvel in UI design.buttons were high up, not square but had a unique shape and the 'printing' went way thru the plastic. surface printing wasn't great on the bezel but buttons were super great.the hp32e stuff that came after had all kinds of plastic problems; I loved that series (had commas in LED and some other neat features) but most of them have rotted with the rear plastic falling apart. that's why I say the hp25 era was the peak of HP calcs. the plastic did hold up, the display was bright and easy to read, the buttons were crisp and you could tell there was pride in its design.I could not care less about programming them; but just USING them, its so much better than 'pressing on glass' (sigh). I'm just NOT a touchscreen kind of person. I think touchscreens are lazy designs.I also seek out power designs power supplies with the amazing rotary machined metal direct-readout knobs.kind of sad that a whole generation will grow up never knowing that there are things beyond touchscreens....

author: Ampera
author_rank: Super Contributor
timestamp: February 17, 2018, 06:10:41 am
content: I always have to friggin screech when I see someone stick a computer motherboard naked onto their bed to take a picture. It also pisses the heck out of me when they just entomb them in normal bubble wrap without any antistatic protection.The good thing is the E-Bay's buyer protections allow you to take chances if you are willing to deal with them.

author: Cyberdragon
author_rank: Super Contributor
timestamp: February 17, 2018, 06:34:00 am
content: I wouldn't expect something to be so poorly designed it would blow up without the battery either! Of course, we EEs have a "magic smoke reflex" to unplug stuff at the first sign of trouble. Poor Joe Bloes don't have this, thus they create magic smoke, inhale it and lose brain cells, then create more magic smoke, lose more brain cells, exc.P.S. thanks for the warning. If I ever find one of these I'll get the power specs then immediately toss the terrible adaptor (maybe after cutting the plug off). Unless there's a way to fit a capacitor in it?

author: CNe7532294
author_rank: Regular Contributor
timestamp: February 17, 2018, 06:35:01 am
content: On topic yeah I hate it when stupid people get a hold of something because they see the price its going for and go YES I STRUCK GOLD BABY! CHA CHING! This happened to me with 2 AFG3252 and 3 AFG3252C. Massive reseller sees they get listed for $5000 or $10000 and instantly buys all of the stock at $1500 or $3000 each. The C model stuck a nerve the most since it had tek's warranty and there were 3 models offered but all bought out. I hate it when they rent it out to make up not reselling too cause then it just accumulates dirt and possible damage by people who don't care.On the positive side though I have gotten deals by the same people who thought piece of a part=junk. Managed to get a working RYTHM 5086-7884 for $300! (my original intent was to study a broken unit). So it all balances out I guess. Who knows keep searching and you'll get that calculator or rather the parts needed to make them work eventually for a sweet deal. Best part is that most of the younger generation only cares for the latest hyped tech anyways. Sad thing yes but works towards our advantage.

author: SeanB
author_rank: Super Contributor
timestamp: February 17, 2018, 06:54:59 am
content: Quote from: Cyberdragon on February 17, 2018, 06:34:00 amDon't toss it, just open up and put in a boosted zener shunt regulator and a capacitor, so that you have an output a little above the full battery voltage, which means the calculator will not be blown up and when you do replace the cells it will still charge them.

author: linux-works
author_rank: Super Contributor
timestamp: February 17, 2018, 08:18:00 am
content: I use LSD batteries (wow man; I mean, low self discharge) and so in-circuit charging is not needed for the calcs I have. all have been opened, the nicads removed and regular AA's or LSD AA's installed. they're less than 1.5v of normal AA so they need no mods to run in the woodstock calcs.I would agree that it was dumb of HP to use batteries as smoothing devices. the UI is perfect, but I didn't say all aspects of the calc design was perfect

author: linux-works
author_rank: Super Contributor
timestamp: February 17, 2018, 08:19:36 am
content: good link for the hp calc stuff:http://www.keesvandersanden.nl/calculators/woodstock.php

author: Dubbie
author_rank: Unknown
timestamp: February 17, 2018, 08:50:18 am
content: I wouldn’t blame users for this. This is just plain bad design. What other products depend on having a battery present to not blow up when you plug it in? Especially when it only would have taken a couple of extra components.

author: komet
author_rank: Unknown
timestamp: February 17, 2018, 09:14:29 am
content: Sometimes people sell old photographic paper. They take the paper out of the bag and take a picture for the ebay listing.Under white light.

author: tggzzz
author_rank: Super Contributor
timestamp: February 17, 2018, 09:51:20 am
content: Quote from: linux-works on February 17, 2018, 04:34:50 amThat's not necessarily stupidity; ignorance is a sufficient explanation.Ignorance can be cured; stupidity can't.

author: Peabody
author_rank: Super Contributor
timestamp: February 17, 2018, 03:03:39 pm
content: Can I get some clarification on this? I have an HP-38C calculator, which I believe is a "Spice" series calculator, and it's still my go-to calculator unless I need to do hex or binary. I am hopelessly confused by this rubbish "=" key in other calculators.I replaced the nicad AAs with nimh some time ago, but still use the HP charger. Actually, "charger" is being generous. The charger output is 10VAC. So all the charging smarts are in the calculator. Are you saying I should never attempt to run it without the batteries installed? I can't remember for sure if I've ever tried to do that, but I don't think so.Then the other question is whether the calculator will properly charge nimh batteries. It seems to do ok, and I never leave it charging for more than a few hours. I assumed that I might not be getting a full charge, but as long as things didn't heat up I was probably ok. Anyone know for sure about that? I remember the manual saying that charging nicads with the calculator turned off would take 5-6 hours, so it's not a fast charge system.

author: PlainName
author_rank: Super Contributor
timestamp: February 17, 2018, 03:37:48 pm
content: QuoteFLiR InfraCAM, all £5000 of it.OK, it doesn't blow up but it is unusable when powered from the (FLiR) wallwart unless the batteries are not just in place but working well too.

author: TK
author_rank: Super Contributor
timestamp: February 17, 2018, 03:57:19 pm
content: Probably they found the vintage calculator / equipment in the attic, so you cannot blame them. You cannot expect everybody to know every detail about everything that exists in the universe. It is like people touching up old painting or fixing antique items before selling them...

author: evava
author_rank: Regular Contributor
timestamp: February 17, 2018, 05:22:36 pm
content: QuoteANY modern car.

author: helius
author_rank: Super Contributor
timestamp: February 17, 2018, 05:41:53 pm
content: Quote from: TK on February 17, 2018, 03:57:19 pmYeah, no.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: February 17, 2018, 05:58:03 pm
content: There is no free lunch. If it weren't for the ignorant flippers those calculators would be out of reach. In a box in an attic somewhere, or in a landfill. If none survived the flippers it would be a shame, but not much of a loss, since the path from that box in the attic to your hands is very narrow and long. The prize in the box is that many do survive the flippers, either because they don't turn it on, or they get lucky.

author: Cyberdragon
author_rank: Super Contributor
timestamp: February 17, 2018, 08:24:22 pm
content: Quote from: evava on February 17, 2018, 05:22:36 pmModern cars have voltage regulators. OLD cars don't.https://www.carparts.com/classroom/charging.htm

author: SeanB
author_rank: Super Contributor
timestamp: February 17, 2018, 09:02:01 pm
content: Old cars had points and condenser, and nothing electronic other than a radio. Then there were alternators, which introduced the diode rectifier but not much more than that aside from the votage regulator inside the alternator. Modern cars now have a lot of electronics in them, and a limited ability to survive the battery disconnect transient, especially at light electrical loading with high engine RPM. The load dump survivability is not going to help long term, you just hope that the fuse blows to disconnect the ECU before it gets too damaged by the high voltage.While alternators typically do have 3 transient suppressor diodes in them, basically 3 of the rectifier diodes being avalanche diodes designed to break down at some voltage between 30-70V on a 12V system, they are also required to pass the 30V breakdown at 150C, so the breakdown is poorly defined, and can be higher when the alternator is cold.

author: ebastler
author_rank: Super Contributor
timestamp: February 17, 2018, 10:16:39 pm
content: Quote from: TwoOfFive on February 17, 2018, 06:10:41 amYes, same here. So easy to snag and tear the bedsheet...

author: Brumby
author_rank: Unknown
timestamp: February 18, 2018, 03:04:27 am
content: Quote from: komet on February 17, 2018, 09:14:29 amOld photographic paper would not be high on my list anyway - but that ... that is ignorance of epic proportions.

author: amspire
author_rank: Super Contributor
timestamp: February 18, 2018, 03:53:54 am
content: Quote from: linux-works on February 17, 2018, 05:34:28 amI love HP calculators, but as soon as the HP11 came out, I couldn't stop using my HP25C fast enough. I never used it again and ended up throwing it out after the batteries leaked a little.The LED displays are cute in a historical way, but they were far too power hungry. To me calculators should last months, not a day (if you are lucky).I have about 9 HP calculators like the HP11C, HP28S, HP32SII, HP35S and multiple HP49Gs. I got 10 HP49Gs for $50. Gave half them away. Not the best keys (I have the model which is better then the original ones) but they are more or less represent the peak of HP calculators in terms of functions and they are Australian designed.I am sorry but I just do not miss the HP25C. Absolutely loved it when I got it, but I was disloyal as soon as I saw the HP11C. The 11C and the 15C are still the perfect calculators to me. I wish HP still made them and the Swiss lookalikes are just not an alternative.

author: linux-works
author_rank: Super Contributor
timestamp: February 18, 2018, 04:21:42 am
content: my eyesight isn't so great after all these years and the hp15c style calcs are more readable (larger fonts); but the red leds are rare today and I remember when they were current (and also on wirstwatches).having grown up with red leds in so many products, I still prefer then, even when they are too small for my older eyes to see well.and the hp15 form factor just never felt good in the hand like the 25 series.battery life; I use rechargeables and the only hassle is to remove them as cells, put them in a charger that's in the kitchen and swap in fresh cells from that same charger. there's no power cord, but my use-case is to turn the calc on, use it for short periods and then turn it off. I have not burned thru a single charge that I can remember; perhaps I'm not a marathon user (and certainly not using them to take school tests, lol).

author: amspire
author_rank: Super Contributor
timestamp: February 18, 2018, 05:39:09 am
content: Quote from: linux-works on February 18, 2018, 04:21:42 amThe HP red led displays were a thing of magic when they came out, and the HP2x series was the first affordable HP scientific calculators. I was at Uni at the time and I remember the big queue to buy the HP21C when it first came out. That was the year the world changed from slide rules and log tables to calculators.I had a HP21C initially, but sold it to someone when the HP25C came out. A nice thing about the HP25C was that is was simple enough to master every feature in the calculator and I used the programmability feature to death, especially as we didn't have PCs at the time. If you had to repeat a calculation 100 times with different data points for a graph, you did the 100 calculations on your calculator. Hardly ever use programming on calculators now, since a spreadsheet does it better.The HP11C works fine flat on your hand or flat on the table since the display is very clear and works at an obscure angle. The displays of my HP49Gs on the other hand are so bad, you have to hold them unless the light is just right.The big thing about the HP11C family is it is probably the only decent RPN calculator designed to fit properly in a shirt pocket.

author: tooki
author_rank: Super Contributor
timestamp: February 21, 2018, 11:47:26 am
content: Quote from: linux-works on February 17, 2018, 04:34:50 amIn all fairness, unless you are an expert on these particular devices, there’s no reason to assume that running them in that configuration is harmful — most devices support that just fine. It’s “ignorance” in the literal sense of not knowing, but certainly not in the sense of willful stupidity. I certainly wouldn’t have known, and I’ve been in tech for decades...So yeah, there were some idiots involved here, but it’s not the eBay vendors, it’s the engineers who designed something that self-immolates in a fairly normal situation.

author: helius
author_rank: Super Contributor
timestamp: February 21, 2018, 02:15:07 pm
content: It's easy to forget in this era of ubiquitous power controller ICs that the world was not always thus. Just pulling the battery pack out and back in while a Powerbook 180c is on mains is enough to kill it.

author: rsjsouza
author_rank: Super Contributor
timestamp: February 22, 2018, 02:22:42 am
content: My dad always warned me about this on his TI59 - the only way to use it without the battery was plugged into the massive printer. Otherwise it would have been gone.On another note, the TI30 had an interesting quirk: as soon as the batteries started to get weak, the calculator would show erratic operations or duplicate numbers, making it look defective - the brownout protection circuitry was not yet invented. I can't help but wonder how many of these were thrown in the garbage by folks believing the calculator has been broken.

author: JoeO
author_rank: Frequent Contributor
timestamp: February 22, 2018, 02:50:25 am
content: Quote from: komet on February 17, 2018, 09:14:29 amI just saw this at a second hand store. Box was opened up and the paper was exposed.

author: amyk
author_rank: Super Contributor
timestamp: February 22, 2018, 03:49:48 am
content: Quote from: JoeO on February 22, 2018, 02:50:25 amDon't the boxes have warnings to keep away from light?

author: JoeO
author_rank: Frequent Contributor
timestamp: February 22, 2018, 11:42:41 am
content: Quote from: amyk on February 22, 2018, 03:49:48 amYes but obviously some people don't want to read warnings.I have seen many items that were broken by people testing them at thrift shops.

author: theleakydiode
author_rank: Regular Contributor
timestamp: February 23, 2018, 11:08:07 am
content: A lot of the sellers on these places don't really know much about what they're selling. Not saying they're all like this but most of the people I've messaged over the years can't really help with technical questions other than what's on a spec sheet. The Chinese ones in particular will just go on about warranties and customer service if I have any problems.Electronics is our thing whilst selling is their's.