Can we have a collection of the worst engineering examples from this beautiful site?

The conditions would be:

  • real, honest example of something that was actually meant seriously
  • some work has went into designing that
  • absolutely no shaming of the original poster, if anything, happy discussion

2 Answers 2


I remember this: Add ground earth to a Chinese music player

Basically a cheap MP3 player with an unisolated supply, that brings 220V mains straight to its line-out/speaker-out jack. Nice.

  • 2
    \$\begingroup\$ This is awesome! Plug in your active headphones, get a new haircut! \$\endgroup\$ Nov 20, 2018 at 12:53
  • \$\begingroup\$ that's amazing! \$\endgroup\$
    – james
    Jan 20, 2019 at 1:57

I'll start with the PCB layout from

Why sometimes some PCB designer add extra traces to connect two pin to each other?

purportedly a 1990s' device from GE

  • R8, R38 shorted out with traces
  • many unpolarized components would have been trivial to route if rotated 180°
  • C3 (large, polarized) and C9 are caps from ground plane to ... same uninterrupted ground plane
  • It says V.2 in the lower left corner

The longer you stare, the more interesting things get.

  • 1
    \$\begingroup\$ Whatever CR1 is (some sort of diode, based on the footprint?) it also appears to be shorted to the same plane. And of course the original question asks why some points are connected through more than one path. \$\endgroup\$
    – DerStrom8
    Nov 19, 2018 at 23:55
  • 4
    \$\begingroup\$ ah, yes, the good ole' ground-ground junction. You know how the voltage difference over a PN junction is always 0.7V, regardless of the current through it? You see, that's how you introduce a static 0.7V potential gradient in a ground plane without an external source of power. Add a boost converter, and BOOOM free energy. \$\endgroup\$ Nov 19, 2018 at 23:58
  • 1
    \$\begingroup\$ @DerStrom8 I'm getting the feeling the layout might be related to this, seeing that it differs only 0.3 in versioning... and there's a CR1 in there! And it's a 1n4733a Zener diode. \$\endgroup\$ Nov 20, 2018 at 0:02
  • \$\begingroup\$ Ahh, good find! I bet you're right. Hmm, I wonder if the OP also used the autorouter.... ;) \$\endgroup\$
    – DerStrom8
    Nov 20, 2018 at 0:05
  • \$\begingroup\$ nah, to be honest, according to OP, the schematics are "100% present correct", and the board presented is "done by a famous company" and "guaranteed to work". So, I think OP is in a tight spot where their experience doesn't allow them to fix the mess they've been handed. (they still could be a bit more open, and frankly, honest about that mess.) \$\endgroup\$ Nov 20, 2018 at 0:08
  • \$\begingroup\$ That would indeed be helpful. \$\endgroup\$
    – DerStrom8
    Nov 20, 2018 at 0:10
  • \$\begingroup\$ A nice mix of 90° traces, 45° and even rounded \$\endgroup\$
    – Curious
    Nov 20, 2018 at 13:49
  • 3
    \$\begingroup\$ @Curious there's also the aerodynamically optimized 15.75° trace in red, left end of the PCB, pretty much vertically centered next to the large blue planes \$\endgroup\$ Nov 20, 2018 at 14:04
  • \$\begingroup\$ So there is! Theres a vast collection of different angled traces it seems! \$\endgroup\$
    – Curious
    Nov 20, 2018 at 14:07
  • \$\begingroup\$ I'm still, again, stuck with explaining OP that he should, in fact, not strive to copy this layout. He's kind of repeating that this is the "working layout" from a "famous company" that he "has to copy as closely as possible". This is exhausting. \$\endgroup\$ Nov 20, 2018 at 14:09

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