PC Front Panel Connector

[CDR_Xavier]

As I have mentioned, I was lucky enough to stumble upon multiple Supermicro systems. And also some others, like Hp, and the like.

We have currently encountered X5DA8, X7DWA-N, X9SRA. X11SLL-F, and maybe X8DAH.

 

We have tested at least 3 boards inside an identical chassis. They always work, and they always have the same header. Might not be the same, but at least compatible.

 

And then I got a W480 from my friend. And the front panel header is different.

 

And then I looked up a Asus W480, and the front panel is different.

 

This is why we can't have nice things -- because apparently, nobody can agree on what the front panel pinout is.

 

I think the Supermicro system is brilliant. The Power and the Reset is always in the same spot (and right on the edge, so jumping with screwdriver is easy).

 

Starting from Pin 5 you start to have "optional features", such as NIC2 LED, NMI (led?), etc.

 

Meanwhile looking at PC side, we have barely figured out the position for the power switch. Now granted, Supermicro is just one company. Tyan does something different as well.

 

..

This is why we can't have nice things. Every case's front panel is just a giant bundle of madness.

[Alex Atkin UK]

57 minutes ago, CDR_Xavier said:

And then I got a W480 from my friend. And the front panel header is different.

 

And then I looked up a Asus W480, and the front panel is different.

 

This is why we can't have nice things -- because apparently, nobody can agree on what the front panel pinout is.

..

This is why we can't have nice things. Every case's front panel is just a giant bundle of madness.

What you are running into are OEM PC designs, where they designed the case and the motherboard to go together so they deliberately do not follow the common layout as they want you using them for all repairs.

When it comes to DIY motherboards, the vast majority of the time they use the same layout these days.  Of course AFAIK its not an official standard, so there can be outliers.

[Blasty Blosty]

My favourite front panel connectors are when they are in a single block from the case, rather than individual little connectors.

[Blasty Blosty]

3 hours ago, Alex Atkin UK said:

What you are running into are OEM PC designs, where they designed the case and the motherboard to go together so they deliberately do not follow the common layout as they want you using them for all repairs.

Capitalism in a nutshell

[Echothedolpin]

3 hours ago, Blasty Blosty said:

Capitalism in a nutshell

Consumerism really, industry standards often fail when no one wants to pay a few dollars more or they choose brand/style over function.

 

edit: I’m being a little contrarian because I really don’t think capitalism is a good catch all excuse for how the world’s economy may or may not be working optimally.

 

Really the issue is that front panel connectors have never been and really don’t need to be standardized. Lots of systems have additional indicators or pass through connections to peripherals that a standardized connector would proscribe.

 

For instance: I was staring at a non standard front panel header last night on a 35 year old system. It was designed to connect over a physical scsi connection, along with some other signals, to consolidate everything on a remote console. It was a really beautiful piece of work in its day, but a pain in the butt if you down own the remote console anymore.

 

 

 

[CDR_Xavier]

10 hours ago, Alex Atkin UK said:

are OEM PC designs

Sort of, but also not exact -- all the Supermicro boards come with .. well, this Supermicro layout. Tyan boards come with Tyan board layouts, and they don't match. It's just like how Gigabyte come with Gigabyte layouts and Asus come with Asus layouts.

There's more in common between Gigabyte and Asus, but those are both consumer boards.

Those, you can easily "fix" by just giving everyone a giant bundle of ketchup and mustard (and spaghetti) cables, probably with individual pins on each (because Tyan). Then you are good.

 

When I think OEM PC Design, I think Optiplex, with the 5-pin power button (green/white + amber LED + button), often coming in different shape and size, and maybe throw together front USB and audio into a single 40-pin high-density ribbon cable, where basically it's impossible to use it without their highly specific case.

Optiplexes also don't print the front panel pinout on the board, because they won't need to worry about someone putting it together.

 

 

My PC's front panel is actually a slim 5.25 inch module, and come with modular cables, so Boxx (yes, that Boxx) can quickly fit it with a custom-pinout connector to fit whatever board that they are to put it into. That's good, because I can just find something that's "Mini-PV" compatiable (think front panel USB and/or audio) housings and wires, and re-crimp them and re-pin them to that custom-pinout front panel. The one it came with is too short anyways.

[Kisai]

11 hours ago, CDR_Xavier said:

As I have mentioned, I was lucky enough to stumble upon multiple Supermicro systems. And also some others, like Hp, and the like.

We have currently encountered X5DA8, X7DWA-N, X9SRA. X11SLL-F, and maybe X8DAH.

 

We have tested at least 3 boards inside an identical chassis. They always work, and they always have the same header. Might not be the same, but at least compatible.

 

And then I got a W480 from my friend. And the front panel header is different.

 

And then I looked up a Asus W480, and the front panel is different.

 

This is why we can't have nice things -- because apparently, nobody can agree on what the front panel pinout is.

 

 

You know what is fun to realize? Desktop PC's all had the same assortment of "front panel" wires since the 80's, but they only changed due to two features being deleted:

- Key lock (locked AT keyboard input)

- Turbo switch

 

The HDD LED, Power LED, Reset SW are unchanged. The ATX Power switch is new, and the PC Speaker header is long gone on MB's.

 

 

With the ATX standard, eventually all vendors switched to a "front panel block" instead of having them as a much of individual headers along the edge of the MB.

 

In the diagrams you showed, the layout is actually the same if  you start from the bottom.

Power

Reset

-undefined-

Overheat

-undefined-

-NIC-

HDD

Power

 

LED's have polarity, so some of these MB's have the anode on the opposite side of the header.

 

So most front panels have these same 1-wire for the switches or 2-wire pin connectors for the LED's if they have the LED's, and if they don't, they don't. Nothing on that front header is required other than the power switch, reset switch and power LED. And many people did not connect the HDD LED since mechanical drives used to have the LED's themselves. With SSD's, the HDD LED isn't meaningful. Likewise the NIC LED's aren't generally meaningful on a device that isn't a server.

 

What I would love is a standard "Front panel header" connector that is just a single wire protocol + power switch+reset switch, that communicates with a microcontroller in the chassis. So a low end chassis would just have it light the power LED, and a high end chassis would have the assortment of HDD, NIC, temperature values, fan values, device name, voltages, etc that could be seen on a front panel LCD. Everything else would just have LED's like now. But this is overcomplicating something that really only is desired in high end systems that have fan and RGB controllers.

 

 

 

 

 

[CDR_Xavier]

31 minutes ago, Kisai said:

In the diagrams you showed, the layout is actually the same if  you start from the bottom.

Yes, because those are all from Supermicro! And they are inter-operable. How nice.

 

It's also not "undefined". They are defined later to be things like "NIC 2". You can have a LED on the front panel, the MB just won't output anything. Or you can not have the LED and just not display that.

This one is from S7025 Tyan (example), good luck with that.

And a s2665 (old Tyan).

 

Doesn't seem like they are compatible. Even Tyan couldn't decide.

 

I used those two as example companies, because both of them make boards you can .. well, purchase. And put into your system. It's not for every consumer. but they nevertheless make components for systems. Such as boards. And mobile-racks. And chassises.

And clearly they aren't trying to prevent you from doing that. They publish the full pinout for all the connectors. And these are all publicly available. You can just .. download.

 

And this one is from my Gigabyte W480 .. something something "W".

And then this one is also from a W480, this time from Asus. And it's different!

But at least the modern consumer main boards have more or less settled on the things highlighted in red. Though the other side's pinout is more random than throwing dices.

 

I will still try to source a "speaker". For both nostalgic and realistic purposes (my PC's side panel is a piece of steel)

[Kisai]

1 hour ago, CDR_Xavier said:

 

 

And this one is from my Gigabyte W480 .. something something "W".

And then this one is also from a W480, this time from Asus. And it's different!

But at least the modern consumer main boards have more or less settled on the things highlighted in red. Though the other side's pinout is more random than throwing dices.

 

I will still try to source a "speaker". For both nostalgic and realistic purposes (my PC's side panel is a piece of steel)

Again, if you start from one side, you'll usually find they are the same pin out to a point. In the case of these last two they are actually the same starting from pin 1, and then the undefined pins in the middle, and then the 4-pin speaker. Chassis intrusion is really the only thing that's in different places. the second PLED is actually what it is because that is what used to be the 5-pin AT keyboard lock and power LED

See, LED, ground, ground, Key switch, ground. You can still connect this to the 5-pins starting at pin 11 on the ASUS board and just the LED part flipped over on the Gigabyte.

 

This is historical precedent for why the pins are where they are.

 

https://commons.wikimedia.org/wiki/File:286_Baby_AT_motherboard_layout.jpg

So the 4-pin speaker and the 5-pin power LED+keylock is that shape, and in the same position as it is on the current ASUS board. This is what the "chassis panel header" was from the beginning.

 

On first generation ATX boards you had stuff like this:

Note the keylock and power LED are 2+3 pins

So on 1997 ASUS vintage systems, the right-hand side had the power and speaker, and the reset, power LED were on the left side of it.

They just moved everything to this "panel" block, it was not designed as a unified 20-pin connector.

 

At any rate the "connectors" that go in  the block have been pretty much standard labeled, but the positions aren't always starting from the same side, usually the speaker and Power LED are on one side, and the other LED's are on the other side.

[Alex Atkin UK]

1 hour ago, CDR_Xavier said:

And this one is from my Gigabyte W480 .. something something "W".

And then this one is also from a W480, this time from Asus. And it's different!

But at least the modern consumer main boards have more or less settled on the things highlighted in red. Though the other side's pinout is more random than throwing dices.

I should have been specific, consumer boards have pretty much settled on "what cases actually use".

 

An alternative option for power connector is for some legacy cases which used that layout, chassis intrusion is uncommon on cases and has nothing to do with the "front panel" and PC speaker could be anywhere in the case also so was always entirely separate.

 

So the point still stands, "front panel connectors" is pretty much standard, the other side is optional and not always included (particularly intrusion, and speaker sometimes is just a beeper on the board) or could be elsewhere on the motherboard.