Worst PCB Ever? - Page 1
Forum section: electronics / general

author: funkyant
author_rank: Unknown
timestamp: June 01, 2017, 10:52:18 am
content: This was a post on Reddit, but was just too good not to share here:https://www.reddit.com/r/electronics/comments/6efm66/worst_pcb_ever/Quote

author: grumpydoc
author_rank: Super Contributor
timestamp: June 01, 2017, 11:01:48 am
content: Wow

author: P90
author_rank: Frequent Contributor
timestamp: June 01, 2017, 11:08:47 am
content: project for modern art class? LOL

author: Zero999
author_rank: Super Contributor
timestamp: June 01, 2017, 11:10:20 am
content: Did they fail or have time to redo it?It looks like it was made in house, are the holes through plated? If so, how was it done?I'm surprised the university got boards made in house, wouldn't it be cheaper to get them done externally?

author: JPortici
author_rank: Super Contributor
timestamp: June 01, 2017, 11:12:28 am
content: was that a fritzing job?

author: funkyant
author_rank: Unknown
timestamp: June 01, 2017, 11:17:34 am
content: Quote from: Hero999 on June 01, 2017, 11:10:20 amI'd make a pretty solid guess that even if they respun it, they still would have failed

author: X
author_rank: Regular Contributor
timestamp: June 01, 2017, 11:22:33 am
content: Quote from: Hero999 on June 01, 2017, 11:10:20 amSome unis actually have their own small-scale silicon fab. Not likely to put Intel out of business, but when research-grade results are required, you'll be surprised at what length unis will go through to ensure they can control the process, which is very handy when you want to keep the number of independent variables under control.

author: CJay
author_rank: Super Contributor
timestamp: June 01, 2017, 11:30:56 am
content: Quote from: funkyant on June 01, 2017, 11:17:34 amFourth year project with four students working as a team, I bloody hope they failed if that was the level of their subject knowledge.

author: funkyant
author_rank: Unknown
timestamp: June 01, 2017, 11:47:26 am
content: Quote from: CJay on June 01, 2017, 11:30:56 amIt's the:Quotethat's really the kicker! hahahahaha

author: Jeroen3
author_rank: Super Contributor
timestamp: June 01, 2017, 11:50:59 am
content: When art students try electronics.

author: amyk
author_rank: Super Contributor
timestamp: June 01, 2017, 11:54:48 am
content: part of me wants to think that this was done as a joke. Then again, given some people I've met...

author: tatus1969
author_rank: Super Contributor
timestamp: June 01, 2017, 01:01:32 pm
content: hard for me to believe this is real. i have to show this to my 14yr old son

author: Ash
author_rank: Regular Contributor
timestamp: June 01, 2017, 01:28:28 pm
content: But it worked in SPICE.....

author: igendel
author_rank: Frequent Contributor
timestamp: June 01, 2017, 01:39:10 pm
content: What's wrong with crossing traces? Electrons that come from the left continue to the right because of momentum, electrons from the top continue to the bottom... it's simple physics people!

author: Cerebus
author_rank: Super Contributor
timestamp: June 01, 2017, 01:40:26 pm
content: Quote from: Hero999 on June 01, 2017, 11:10:20 amWhen I was at university (a relatively small one with ~3500 undergraduates) the university had about 4 student machine shops (excluding the specialist ones for metallurgy and materials science) and two prototype scale PCB shops. How do you expect people to learn if they don't get hands-on experience? If you don't, you end up with people who design things that can't be efficiently manufactured, or even can't be manufactured at all.If you've got the size to have frequent need of some facility it's often cheaper to have it in house; after all, you're not paying someone's profit. Let alone the usefulness of having experienced staff on hand whose job it is to help you get the best, cheapest job done, not the most profitable or easiest to sell. Even if the economic benefits are marginal or even slightly negative, the convenience, access to processes for teaching and access to experienced technicians can make up for the economic angle with those intangible benefits.Aside from teaching related facilities as above, the university also had one main and two satellite professional print rooms as it just made commercial sense to have that much printing capacity. Heck, even the student union had its own print room, that kept an ageing Rotaprint 30/90 in daily use.

author: Dielectric
author_rank: Regular Contributor
timestamp: June 01, 2017, 01:51:52 pm
content: Just checking in to make sure it wasn't one of my boards.

author: mdszy
author_rank: Unknown
timestamp: June 01, 2017, 01:58:56 pm
content: I need to hang a picture of this up in my lab, that way every time one of my own boards fails to develop/etch properly, I can look at this and be thankful I didn't make something like this!

author: CJay
author_rank: Super Contributor
timestamp: June 01, 2017, 02:09:21 pm
content: Quote from: igendel on June 01, 2017, 01:39:10 pmAt certain frequencies that... No.Just no

author: GreggD
author_rank: Regular Contributor
timestamp: June 01, 2017, 02:11:28 pm
content: I have a hard time believing this but if true then not just the students but the school should find something else to do. Hope there are no student loans to be repaid.I want to see the other side of the pcb.

author: 691175002
author_rank: Regular Contributor
timestamp: June 01, 2017, 02:13:14 pm
content: I saw a lot of this kind of thing when I was at university. If you aren't interested enough in the subject to do projects on your own time you just never connect classroom knowledge to the real world.Its more prevalent (but less obviously hilarious) in computer science. If you ask a graduating class to produce a simple application 80% of them will start by implementing a linked list from scratch in C.

author: Zbig
author_rank: Frequent Contributor
timestamp: June 01, 2017, 03:02:49 pm
content: Quote from: 691175002 on June 01, 2017, 02:13:14 pmNo. There's no sensible explanation for this other than them being dumb as a bag of hammers. I knew this thing wouldn't make any kind of sense when I was 10. And I'm not really that smart, either.

author: tszaboo
author_rank: Super Contributor
timestamp: June 01, 2017, 03:13:09 pm
content: Not even close. The worst PCB I saw was some programing board for some old Motorola microcontroller. Obviously it was autorouted. And it had a lot of logic chip on it for the wierd timing programming requirements for the MCU. It had a bunch of NC pins..........Every NC pin was connected together by the autorouter.And of course you dont spin the board again, you solve this with the scalpel. And if you fixed the wrong track, you fix your fix with a bodge wire.

author: mdszy
author_rank: Unknown
timestamp: June 01, 2017, 03:15:20 pm
content: Quote from: NANDBlog on June 01, 2017, 03:13:09 pmPardon my own idiocy... But what's the issue with NC pins getting connected together? If they're not internally connected to anything, what does it matter how they're routed?

author: Zbig
author_rank: Frequent Contributor
timestamp: June 01, 2017, 03:19:48 pm
content: Quote from: mdszy on June 01, 2017, 03:15:20 pm"Don't connect" often really means "don't connect" and not "don't care where you connect this as it's floating anyway". It's often some factory test connection or such.

author: rfdes
author_rank: Regular Contributor
timestamp: June 01, 2017, 03:23:34 pm
content: This smells like a bogus post. i.e. fake.

author: Muxr
author_rank: Super Contributor
timestamp: June 01, 2017, 03:26:27 pm
content: That student definitely does not have the knack.

author: tszaboo
author_rank: Super Contributor
timestamp: June 01, 2017, 03:34:42 pm
content: Quote from: Zbig on June 01, 2017, 03:19:48 pmNot only that, but the guy decided to call a bunch of pins NC. Like there was a counter, and most of the outputs were NC...

author: mdszy
author_rank: Unknown
timestamp: June 01, 2017, 03:55:07 pm
content: Quote from: NANDBlog on June 01, 2017, 03:34:42 pmOhhh, they weren't NC pins on the device, but were marked as NC in the schematic and all shorted together? Yikes!

author: CJay
author_rank: Super Contributor
timestamp: June 01, 2017, 03:59:57 pm
content: Even if they were NC it's always a good idea to check and see what the datasheet suggests for them, sometimes you find out that you can improve circuit performance by connecting them to ground, VCC or whatever.

author: Bud
author_rank: Super Contributor
timestamp: June 01, 2017, 04:45:19 pm
content: NC pins can be used by the manufacturer for internal testing. As the other post said, check the datasheet what it says. If says nothing leave them alone and do not connect together.

author: jonovid
author_rank: Super Contributor
timestamp: June 01, 2017, 05:27:00 pm
content: looks like schematic diagram went straight to pcb, oowps!forgot the pcb layout!no altium or EAGLE used here.

author: skarecrow
author_rank: Regular Contributor
timestamp: June 01, 2017, 05:27:12 pm
content: Quote from: igendel on June 01, 2017, 01:39:10 pmNo, crossing the traces would be just like crossing the streams. It would be bad. Sent from my XT1565 using Tapatalk

author: grifftech
author_rank: Frequent Contributor
timestamp: June 01, 2017, 05:59:25 pm
content: Quote from: skarecrow on June 01, 2017, 05:27:12 pmthis works

author: skarecrow
author_rank: Regular Contributor
timestamp: June 01, 2017, 06:12:36 pm
content: Quote from: grifftech on June 01, 2017, 05:59:25 pmOMG they crossed the streams! Egon was wrong!Sent from my XT1565 using Tapatalk

author: X
author_rank: Regular Contributor
timestamp: June 01, 2017, 06:49:00 pm
content: One of the Reddit users made a good point about the possibility that this was purposely rushed:Quote from: Reddit user "upofadown"Perhaps the students aren't so dumb and they have excellent time management skills and can work within constraints.

author: xrunner
author_rank: Super Contributor
timestamp: June 01, 2017, 06:56:56 pm
content: Mixing modern art and electronics - what's the big deal?

author: janoc
author_rank: Super Contributor
timestamp: June 01, 2017, 07:34:17 pm
content: Quote from: 691175002 on June 01, 2017, 02:13:14 pmI can concurr - I did teach at a uni and the things we got to see from time time ... mind boggles.Quote from: 691175002 on June 01, 2017, 02:13:14 pmWell, I had undergrads give me blank stares and then claim that my blackboard calculation is wrong, because "it is not what the calculator says!". Guess what - I have used fractions. Elementary school stuff. Total Chinese to them.Or something like operator priorities - no idea. Many students I had kept punching numbers into calculators until one combination "worked" and gave the expected result. Thank God for the modern calculators that can handle such difficult problems like multiplying before adding for them.Another such horror was a computer science master final year (!!!) student in a computer vision course who couldn't multiply two matrices. When confronted with it (it is freshman year stuff), he claimed he has never needed it - even though computer vision pretty much cannot be done without them and he has passed several other courses where they were needed.So I can perfectly believe that the board posted by OP is real. Not everyone going to university and studying an engineering curriculum actually has the mental faculties for it. However, many are often very good at "winging it" just well enough to pass when there are too many students or the teacher/TA doesn't really care (exam resits mean extra work).Teaching is not rewarded, at most unis you don't get any credit for it, so many profs will do only the bare minimum required. If you don't and try to care about what your students are doing you are actually shooting yourself in the foot, because then you don't have time for research and writing papers - which are directly tied to your lab's budget and the extension (or not) of your contract or chances at tenure.Speaking from experience - spent 4 years as an assistant professor, had two semesters where I have been running 10 different courses with no TAs (insane!), the rest were 3-5 courses (normal load is 1-2 courses max). Then was told that "sorry, but your contract will not be renewed, we don't have an associate position for you". The guy who got it instead was a terrible teacher, but he was churning out papers like a printing press (and knew who to rub shoulders with). I had two papers published in that time - with 10 courses on my back I had barely time to prepare the classes and go to bed in time to get at least few hours sleep before another day of lecturing.The result of this are university grads that are barely able to add two numbers together ...

author: john_c
author_rank: Contributor
timestamp: June 01, 2017, 08:30:47 pm
content: Quote from: Jeroen3 on June 01, 2017, 11:50:59 amQuote from: xrunner on June 01, 2017, 06:56:56 pmWhoa, whoa. I'm an artist. Please don't make comments like that predicated on the idea that artists are stupid. Whoever made that PCB is a garden-variety dummy.

author: Zero999
author_rank: Super Contributor
timestamp: June 01, 2017, 09:05:09 pm
content: Quote from: funkyant on June 01, 2017, 11:17:34 amWhat CAD software did they use? M$ Paint?

author: mdszy
author_rank: Unknown
timestamp: June 01, 2017, 09:06:25 pm
content: Quote from: Hero999 on June 01, 2017, 09:05:09 pmAlmost looks to me like they just used a sharpie and a straightedge or something haha.

author: CJay
author_rank: Super Contributor
timestamp: June 01, 2017, 09:18:34 pm
content: Quote from: mdszy on June 01, 2017, 09:06:25 pmHey, I've used both, I've even transcribed PCBs from magazine layouts using straight edge and a bowspring compass. All of them were better than that thing...

author: ZeTeX
author_rank: Frequent Contributor
timestamp: June 01, 2017, 09:18:43 pm
content: How can such an idiot be at Universityhow

author: Cerebus
author_rank: Super Contributor
timestamp: June 01, 2017, 09:21:37 pm
content: Quote from: mdszy on June 01, 2017, 09:06:25 pmExcept that the annular rings on the through holes look really neat and even, suggesting that itwasproduced with a actual PCB CAD package. If that's the case, how the frig did they manage to make such a pig's ear of the rest?

author: 691175002
author_rank: Regular Contributor
timestamp: June 01, 2017, 09:45:07 pm
content: Quote from: ZeTeX on June 01, 2017, 09:18:43 pmI've had a masters in EE tell me that its impossible for the battery charger to be outputting 2A at 12V because the benchtop supply it was being powered from was only showing 1.2A of output (at 24V). He simply could not understand that a device could output more amps than it was taking in.This was back when I still thought these people could be reasoned with, so I wasted about half an hour explaining that amperage is not power, and playing with the voltage knob to show that more amps are drawn at lower voltages.The discussion was heated and went nowhere. To be fair his research was in computer vision, but this is the kind of stuff you see a lot of.

author: Muxr
author_rank: Super Contributor
timestamp: June 01, 2017, 11:51:02 pm
content: Quote from: ZeTeX on June 01, 2017, 09:18:43 pmAs a soft. eng I've worked with some PhD's who were very mediocre coders. I mean they were not terrible, just not anything special. And some of the most brilliant guys I've worked with were college dropouts.It really comes down to passion. Passion and hard work is like 90% it imo. A formal education can help but if you don't have the passion for it it doesn't mean all that much.Jim Williams is a great example.Also some people end up going to a wrong school. They don't know what they want to be before they go to uni. Like after they enroll they realize that's not the field they want to be in. I feel bad for those who don't find the field they enjoy. I was lucky I knew exactly what I wanted to be when I was like 10 years old.

author: amyk
author_rank: Super Contributor
timestamp: June 02, 2017, 12:46:31 am
content: Quote from: X on June 01, 2017, 06:49:00 pmYou usually get 0 marks for not doing something. These students should be gettingnegativemarks.

author: P90
author_rank: Frequent Contributor
timestamp: June 02, 2017, 12:49:55 am
content: Quote from: 691175002 on June 01, 2017, 09:45:07 pmpowered from 3-phase 120Hz DC... :-)

author: james_s
author_rank: Super Contributor
timestamp: June 02, 2017, 12:58:07 am
content: This has got to be a joke. There's no way a group of students made it to 400 level classes without being able to do better than that.

author: P90
author_rank: Frequent Contributor
timestamp: June 02, 2017, 01:00:02 am
content: yes, it's obviously a joke...

author: StillTrying
author_rank: Super Contributor
timestamp: June 02, 2017, 01:01:08 am
content: If the crossing tracks really were joined to each other there'd be a round blob at the crossing points, so it should work OK.I think it's real.

author: Someone
author_rank: Super Contributor
timestamp: June 02, 2017, 03:01:43 am
content: Quote from: james_s on June 02, 2017, 12:58:07 amQuote from: P90 on June 02, 2017, 01:00:02 amYou've probably never taught students then, those lagging behind and scraping their way through the prerequisites can have astoundingly poor understanding of the material and get by with combinations of "group work" where they don't contribute anything that helps the group (or hinders it), "tutoring" assistance with their assignments, and in extreme cases "substitutes" in tests. The really surprising part is they don't see any moral issues with it and will justify how they are entitled to all the assistance they need to pass.The best example I can provide was a final year electronic major, who given all the resources of the laboratory couldn't measure or even describe current. You can't even laugh about it at that point.

author: mdszy
author_rank: Unknown
timestamp: June 02, 2017, 03:06:09 am
content: Quote from: Someone on June 02, 2017, 03:01:43 amI was about to rage about "How could someone like that even be allowed to get a degree?!!!" but then realized: they're completely unhireable and will just end up getting a crappy job unrelated to their degree , which they likely are in massive debt for!

author: Someone
author_rank: Super Contributor
timestamp: June 02, 2017, 03:12:55 am
content: Quote from: StillTrying on June 02, 2017, 01:01:08 amThats the sort of thinking that would lead to this. You could produce clever laboratory work where the students would need to simulate the design and then measure the real world and determine why it differs, very few would ever be able to come up with the answer. I could fully imagine a group of clueless students (having failed to attach themselves to competent partners/groups) sitting around the schematic in simulation and just dropping that onto a board without a DRC or any forward annotation.

author: jwm_
author_rank: Frequent Contributor
timestamp: June 02, 2017, 04:39:46 am
content: My guess about how this came about is that they attempted to split up the work.among the 4 person team. One person got schematic, another got theory and one dude got the make the PCB task. PCB guy probably slacked to the last minute, claiming he was on top of it, not asking for help because he already said he started it, until the night before it was due. Whipped this up, but wasnt the schematic or theory guy so didn't realize it wouldn't work. Brought it to his team members a half hour before it was due and they were like.. WTF. But soldered the components in anyway to turn it in so as to not get a zero, horribly embarrassed the whole time and shooting daggers at the PCB guy. Not a fan of group assignments.

author: james_s
author_rank: Super Contributor
timestamp: June 02, 2017, 05:43:31 am
content: I rarely liked group assignments either. With the right group they worked really well, but it was too easy to end up with some slacker who was just along for the ride.

author: CJay
author_rank: Super Contributor
timestamp: June 02, 2017, 07:16:15 am
content: Quote from: blueskull on June 02, 2017, 04:10:29 amI found the best students were always those who took the courses to certify their skills, I.E. they were long term hobbyists who were probably, in knowledge terms, already at degree level before they started and just needed to be taught how to apply it.They were the 'self starters' who, when tasked or even just shown a new technology, devoured it if it interested them.One of my responsibilities in a long left job was to manage university students on work experience placements, they were almost without exception, utterly bloody useless, most freely admitted they'd taken the course because of the financial prospects and not because of any interest in it.The very best, one who stands out in my memory (I'd love to know what happened to him) was a guy called Andy Papageorgiou who was in the middle of designing a Transputer based machine that got published in one of the electronics magazines of the time (mid 80s, if anyone has scans...).

author: Red Squirrel
author_rank: Super Contributor
timestamp: June 02, 2017, 07:43:28 am
content: lmao at the overlapping traces. I think they were so used to seeing it in circuit diagrams where if you don't put a dot it means the lines arn't touching, that they actually took that literally in the PCB design.

author: Zbig
author_rank: Frequent Contributor
timestamp: June 02, 2017, 09:44:50 am
content: Quote from: 691175002 on June 01, 2017, 09:45:07 pmI've hada teacherin my technical high school look down at me in disgust because, during the lab class, I haven't hooked up an ammeter just after the PSU (as the instructions called for) but took the readings off the meter conveniently built into the PSU instead (only some newer ones they've got had them). She said something along the lines of "and how on Earth do you think the current would have ended upinsidethe power supply!?". She just couldn't wrap her head around the idea that the current doesn't magically appear on the positive output terminal and then disappear to another dimension into the negative one. It was just too much for her to comprehend. Jeez, how I hated that woman. I think it was also her who insisted that the optocoupler working principle as explained in the book was just a kind of a "metaphor" to make understanding of the concept easier as she figured it would be impossible and/or silly for an actual LED to be shining on an actual phototransistor inside the IC package

author: CJay
author_rank: Super Contributor
timestamp: June 02, 2017, 09:49:03 am
content: Quote from: Zbig on June 02, 2017, 09:44:50 amYour opto coupler comment piqued my interest, I've always taken it as read that there was a LED and phototransistor inside the package, probably as two separate die with some sort of transparent filler between, now I need to go and chisel one open to find out for myself*edit*Ah, the 'net to the rescue, x-ray images are brilliant. Though there's a 4N35 that's going to meet the Dremel this evening anyway...

author: TerraHertz
author_rank: Super Contributor
timestamp: June 02, 2017, 12:17:52 pm
content: While I agree with everyone saying there are plenty of completely clueless electronics undergrads, I still think this is someone trolling. The original post is this:http://imgur.com/gallery/i8MEXctWhere there's zero evidence this was real.If the photo was taken in a university lab environment, why not include some context in the frame?

author: Cerebus
author_rank: Super Contributor
timestamp: June 02, 2017, 12:37:23 pm
content: Quote from: mdszy on June 02, 2017, 03:06:09 amYeah, the problem is that unrelated job is "Management" and you get to call them "Boss".

author: pitagoras
author_rank: Regular Contributor
timestamp: June 02, 2017, 12:41:54 pm
content: Quote from: igendel on June 01, 2017, 01:39:10 pmThey could have even fix it with miniature traffic lights in the corners

author: igendel
author_rank: Frequent Contributor
timestamp: June 02, 2017, 12:57:46 pm
content: Quote from: pitagoras on June 02, 2017, 12:41:54 pmNow that's some original, out-of-the-box thinking! You're hired!

author: madires
author_rank: Super Contributor
timestamp: June 02, 2017, 01:06:07 pm
content: Promising candidate for a senior consultant at Accidenture

author: ZeTeX
author_rank: Frequent Contributor
timestamp: June 02, 2017, 01:27:11 pm
content: Quote from: pitagoras on June 02, 2017, 12:41:54 pmAnd add a hospital in case one of the electrons crash into another

author: janoc
author_rank: Super Contributor
timestamp: June 02, 2017, 02:00:14 pm
content: Quote from: mdszy on June 02, 2017, 03:06:09 amYou don't realize that these guys are not there to get hired as EE (or another type) engineer. They are there to get a degree, often choosing the school only because it was easiest to get in or simplest to get visa or having cheapest tuition. Then they go home and become managers.Not joking - had exactly this happen with some international students. Getting western education is a matter of prestige there, regardless of whether the student needs it or wants it. So they "study". All they really want is the graduation paper, in most cases they will never touch the subject they have studied in their lives anymore. One such guy got almost expelled for cheating, totally incompetent, barely scraped by but colleagues let him graduate. Now he is a C-level exec at a major company in Singapore laughing at how stupid we were working for the pittances we were paid.I have met even a French guy (so it is not just international/third world stuff) who has been *proud* (and bragging about it) that someone else wrote his thesis and did his final project for him (under his "management"!). He was dumb as a brick, of course, anything he touched with his management "skills" turned into a major clusterfuck. And that fraud has almost managed to get a tenure at a fairly prestigious technical university by bullying ("managing") others to credit him for work he didn't do. He would have got it if there wasn't for one prof who actually knew him personally and put a kibosh on it by vetoing the process.

author: tatus1969
author_rank: Super Contributor
timestamp: June 02, 2017, 05:31:18 pm
content: Quote from: pitagoras on June 02, 2017, 12:41:54 pmDon't underestimate the abilities of these tiny little electrons, they have gone through worse than that. Below is a diagram showing their tricks with a BJT. Don't believe all that theoretical explanations with semiconductor junctions and charge carriers, this is how they really do it!

author: pitagoras
author_rank: Regular Contributor
timestamp: June 02, 2017, 05:43:07 pm
content: Quote from: ZeTeX on June 02, 2017, 01:27:11 pmProblems arise when there is no electricity, traffic lights would not work, so we need also little policeman to take over the situation.

author: Red Squirrel
author_rank: Super Contributor
timestamp: June 03, 2017, 05:08:33 am
content: Quote from: pitagoras on June 02, 2017, 05:43:07 pmOr just make it a 4 way stop, you can even put "no left turns" and "no right turns" signs to ensure they go the right way. Violators are just seen as noise and are the reasons for error correction further down the line, so you need a correctional facility in the circuit.

author: German_EE
author_rank: Super Contributor
timestamp: June 03, 2017, 07:04:15 am
content: "Or just make it a 4 way stop, you can even put "no left turns" and "no right turns" signs to ensure they go the right way."Which is roughly what a microwave circulator does, I've always thought that a little bit of magic was involved with them.https://en.wikipedia.org/wiki/Circulator