Author Topic: Worst PCB Ever?  (Read 15095 times)

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Offline rfdes

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Re: Worst PCB Ever?
« Reply #25 on: June 01, 2017, 03:23:34 pm »
This smells like a bogus post.  i.e. fake.  ;D
 

Offline Muxr

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Re: Worst PCB Ever?
« Reply #26 on: June 01, 2017, 03:26:27 pm »
That student definitely does not have the knack.

 
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Online NANDBlog

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Re: Worst PCB Ever?
« Reply #27 on: June 01, 2017, 03:34:42 pm »
Pardon 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?

"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.
Not 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...
 

Offline mdszy

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Re: Worst PCB Ever?
« Reply #28 on: June 01, 2017, 03:55:07 pm »
Pardon 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?

"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.
Not 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...

Ohhh, they weren't NC pins on the device, but were marked as NC in the schematic and all shorted together? Yikes!
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Offline CJay

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Re: Worst PCB Ever?
« Reply #29 on: June 01, 2017, 03:59:57 pm »
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.

 

Online Bud

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Re: Worst PCB Ever?
« Reply #30 on: June 01, 2017, 04:45:19 pm »
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.
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Offline jonovid

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Re: Worst PCB Ever?
« Reply #31 on: June 01, 2017, 05:27:00 pm »
looks like schematic diagram went straight to pcb, oowps!  :palm: forgot the pcb layout!  :-//  no altium or EAGLE used here.  :-DD
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Offline skarecrow

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Re: Worst PCB Ever?
« Reply #32 on: June 01, 2017, 05:27:12 pm »
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!  :-DD
No, crossing the traces would be just like crossing the streams.  It would be bad.  [emoji51]

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Offline grifftech

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Re: Worst PCB Ever?
« Reply #33 on: June 01, 2017, 05:59:25 pm »
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!  :-DD
No, crossing the traces would be just like crossing the streams.  It would be bad.  [emoji51]

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this works :D
 
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Offline skarecrow

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Re: Worst PCB Ever?
« Reply #34 on: June 01, 2017, 06:12:36 pm »
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!  :-DD
No, crossing the traces would be just like crossing the streams.  It would be bad.  [emoji51]

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this works :D

OMG they crossed the streams! Egon was wrong!

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Offline X

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Re: Worst PCB Ever?
« Reply #35 on: June 01, 2017, 06:49:00 pm »
One of the Reddit users made a good point about the possibility that this was purposely rushed:
Quote from: Reddit user "upofadown"
Probably an example of a clever strategy. If you don't have enough time to do everything you have to decide what you can dump. Projects take a lot of time and don't generate a lot of marks. Even if you can't find someone to fix it for you there might still be some marks in it and since you didn't spend any time on it those marks are basically free.

... and heck ... maybe you will get really really lucky and the thing will work in some sense. Sometimes when you are underwater, luck is all you got.

One of the most important life skills you learn in engineering school is how to do a half assed job quickly.
Perhaps the students aren't so dumb and they have excellent time management skills and can work within constraints.
« Last Edit: June 01, 2017, 06:50:52 pm by X »
 

Online xrunner

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Re: Worst PCB Ever?
« Reply #36 on: June 01, 2017, 06:56:56 pm »
Mixing modern art and electronics - what's the big deal?  :-//
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Online janoc

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Re: Worst PCB Ever?
« Reply #37 on: June 01, 2017, 07:34:17 pm »
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.

I can concurr - I did teach at a  uni and the things we got to see from time time ... mind boggles.

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.

Well, 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 ...

« Last Edit: June 01, 2017, 07:44:33 pm by janoc »
 
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Offline john_c

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Re: Worst PCB Ever?
« Reply #38 on: June 01, 2017, 08:30:47 pm »
When art students try electronics.

Mixing modern art and electronics - what's the big deal?  :-//

Whoa, 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.

 

Offline Zero999

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Re: Worst PCB Ever?
« Reply #39 on: June 01, 2017, 09:05:09 pm »
Did they fail or have time to redo it?

I'd make a pretty solid guess that even if they respun it, they still would have failed  :-DD
What CAD software did they use? M$ Paint?
 

Offline mdszy

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Re: Worst PCB Ever?
« Reply #40 on: June 01, 2017, 09:06:25 pm »
Did they fail or have time to redo it?

I'd make a pretty solid guess that even if they respun it, they still would have failed  :-DD
What CAD software did they use? M$ Paint?

Almost looks to me like they just used a sharpie and a straightedge or something haha.
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Offline CJay

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Re: Worst PCB Ever?
« Reply #41 on: June 01, 2017, 09:18:34 pm »
Did they fail or have time to redo it?

I'd make a pretty solid guess that even if they respun it, they still would have failed  :-DD
What CAD software did they use? M$ Paint?

Almost looks to me like they just used a sharpie and a straightedge or something haha.

Hey, 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...
 

Offline ZeTeX

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Re: Worst PCB Ever?
« Reply #42 on: June 01, 2017, 09:18:43 pm »
How can such an idiot be at University
how  :palm:
 

Online Cerebus

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Re: Worst PCB Ever?
« Reply #43 on: June 01, 2017, 09:21:37 pm »
Almost looks to me like they just used a sharpie and a straightedge or something haha.

Except that the annular rings on the through holes look really neat and even, suggesting that it was produced 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?
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 

Offline 691175002

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Re: Worst PCB Ever?
« Reply #44 on: June 01, 2017, 09:45:07 pm »
How can such an idiot be at University
how  :palm:

I'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.
 

Offline Muxr

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Re: Worst PCB Ever?
« Reply #45 on: June 01, 2017, 11:51:02 pm »
How can such an idiot be at University
how  :palm:
As 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.
« Last Edit: June 01, 2017, 11:59:24 pm by Muxr »
 

Offline amyk

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Re: Worst PCB Ever?
« Reply #46 on: June 02, 2017, 12:46:31 am »
One of the Reddit users made a good point about the possibility that this was purposely rushed:
Quote from: Reddit user "upofadown"
Probably an example of a clever strategy. If you don't have enough time to do everything you have to decide what you can dump. Projects take a lot of time and don't generate a lot of marks. Even if you can't find someone to fix it for you there might still be some marks in it and since you didn't spend any time on it those marks are basically free.

... and heck ... maybe you will get really really lucky and the thing will work in some sense. Sometimes when you are underwater, luck is all you got.

One of the most important life skills you learn in engineering school is how to do a half assed job quickly.
Perhaps the students aren't so dumb and they have excellent time management skills and can work within constraints.
You usually get 0 marks for not doing something. These students should be getting negative marks.
 
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Offline P90

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Re: Worst PCB Ever?
« Reply #47 on: June 02, 2017, 12:49:55 am »
How can such an idiot be at University
how  :palm:

I'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.

powered from 3-phase 120Hz DC... :-)
 
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Offline james_s

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Re: Worst PCB Ever?
« Reply #48 on: June 02, 2017, 12:58:07 am »
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.
 

Offline P90

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Re: Worst PCB Ever?
« Reply #49 on: June 02, 2017, 01:00:02 am »
yes, it's obviously a joke...
 


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