68kMLA Classic Interface
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| The most horrible USB card layout I’ve ever seen | |
| Posted by: croissantking on 2024-08-05 12:46:39 Knowing a bit about USB 1.1 interfaces now, I thought I’d share images of this card I got off eBay sold as working. It has no inline ferrite beads on the data lines or fuses on Vbus, basically no form of hot plug/overcurrent protection at all. Two of the traces on the back have burned through! Also, most cards like this have lots of 100nF filter caps connected to the USB chip, whereas this card has none. The designers can’t have just overlooked the datasheets, they must have known what they were doing.   | |
| Posted by: cheesestraws on 2024-08-05 13:19:48 oooh, toasty. | |
| Posted by: Mk.558 on 2024-08-05 16:18:44 But it passed QC! | |
| Posted by: croissantking on 2024-08-05 16:29:46 🤣 | |
| Posted by: finkmac on 2024-08-05 16:32:33 this really puts the "hot" in "hot-plug" i think | |
| Posted by: NJRoadfan on 2024-08-05 16:35:22 True Story: A bunch of big name motherboard makers decided to skimp on ESD protection on their USB ports when building Intel i865 based boards. Enough of them blew up that a recall had to be issued. | |
| Posted by: Iesca on 2024-08-05 16:44:01 Oops, it actually is through-hole mounted, my bad! | |
| Posted by: alectrona6400 on 2024-08-05 17:37:25 mmmmm toasty. peak expansion card design. /s | |
| Posted by: Arbee on 2024-08-05 17:41:11 That is what "built to a price" looks like. Also, if that's really version 7.0 I'd hate to see the first 6. | |
| Posted by: chelseayr on 2024-08-05 18:12:54 i'm just sleepingly joking (yeah i need to go to bed very soon so..) but I wonder if the very first version maybe had absolutely nothing but just the one lone opti ic chip alone on it? talk about trying to figure how little to get away with in a somewhat weird way to do it? | |
Posted by: sfiera on 2024-08-05 18:53:07Two of the traces on the back have burned through!OPTi “FireLink” chip working as intended. | |
Posted by: croissantking on 2024-08-05 19:19:59True Story: A bunch of big name motherboard makers decided to skimp on ESD protection on their USB ports when building Intel i865 based boards. Enough of them blew up that a recall had to be issued.Crazy b*stards | |
| Posted by: Mk.558 on 2024-08-05 19:29:57 I was looking again at this board and was wondering: Got ground plane? That's a bigger ground plane than a small Serbian village. Maybe we should route the +5V and GND over those.  Shirley it won't burn up the host motherboard trying to draw 20 Amps through it? | |
Posted by: Arbee on 2024-08-06 09:06:23I was looking again at this board and was wondering: Got ground plane? That's a bigger ground plane than a small Serbian village. Any cuts to the PCB that aren't to meet the PCI spec add cost and manufacturing complexity, so it's a big empty rectangle. Same idea with not etching most of the copper layer, probably. | |
Posted by: demik on 2024-08-06 10:58:05Knowing a bit about USB 1.1 interfaces now, I thought I’d share images of this card I got off eBay sold as working. It has no inline ferrite beads on the data lines or fuses on Vbus, basically no form of hot plug/overcurrent protection at all. Two of the traces on the back have burned through!Plot twist: the traces ARE the overcurrent protection 😆 | |
| Posted by: Mk.558 on 2024-08-06 17:36:03 Oh I'm aware that the more traces you plot into your board the more expensive it is. I was just being sarcastic. | |
Posted by: 68kPlus on 2024-08-06 19:05:59Plot twist: the traces ARE the overcurrent protection 😆The traces act as fuses 😀 | |
Posted by: croissantking on 2024-08-07 04:04:54The traces act as fuses 😀Haha indeed, I underestimated the ingenuity of these card makers. | |
| Posted by: Forrest on 2024-08-09 15:57:48 I was a Manufacturing Engineer in the PCB business for many years. My opinion is someone has intentionally applied WAY more current to that board than was required. 500 mA at 5V (USB maximum) will not blow those large traces off the board. You need about 100V at 15 Amps to do that kind of damage. | |
Posted by: Iesca on 2024-08-09 19:38:56You need about 100V at 15 Amps to do that kind of damage.Naughty naughty! | |
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