SOLVED Asrock C2550DI with SuperMicro SuperChassis - Header Pinout

[storage-junkie]

Hello - I am looking for some help with my current build. I am using the following components:

Chassis:
https://www.amazon.com/gp/product/B00REWHHNU/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

MB:
https://www.amazon.com/gp/product/B00GG94YDS/ref=ox_sc_sfl_title_2?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

I'm using this adapter to connect the chassis front panel status lights:
https://www.amazon.com/gp/product/B000VUJYTW/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

One issue I'm having is that the pinouts for the front panel do not match up to the headers on the Asrock MB. For example, the wiring harness has a OH LED, PWR FAIL wire, but I don't see a place to connect those according to the board manual. The other issue is that the PWR LED wire is a three pin, but the Asrock board expects it to be a two pin.

This is surprising to me I thought this board / chassis combination is very popular together, but it's looking like i'm going to have to either re-wire the PWR LED or get another adapter, and I'm going to have two status leads that just don't connect to anything. Am I missing something here?

 

[jgreco]

The Supermicro headers are dense because in some cases they assume that some of your LED's may have a common ... can't remember if it is ground or 5V off the top of my head.

A Supermicro board works with the chassis to provide alarms for things like overheat ("OH LED") and power failure ("PWR FAIL") which are bits of information sourced from sensors on the mainboard and over the PMBus from the redundant power supplies. These are generally driven by the IPMI/BMC subsystem. However, they are nonstandard things that Supermicro has provided because server owners expect the server equivalent of automotive dashboard idiot lamps. They may not translate to any capability that the ASRock board has.

You can trivially fix the PWR LED issue. Look carefully at the housing at the three little holes on the side. Notice that they are actually tiny plastic tabs. Take an Xacto knife tip, or a pin, or a staple, and gently lift up the tab about half a millimeter. While doing that, gently tug on the wire and the pin will come out. Make sure to keep the same orientation and insert it in the middle channel until it clicks in place.

 

[storage-junkie]

Thanks so much for your detailed response! I got the wiring harness for the PWR LED switched out with one of the unused two-pin harnesses, and got everything connected, but none of the status lights on the front panel are coming on. And I've double checked the manual and verified that they're all connected to the correct positions. The only thing that works is the power switch. The power light, hdd, network or info lights don't work at all. I kind of assumed the info light wouldn't work, but I at least expected the power light to function!

 

[Redcoat]

You may have the polarities reversed. The network light will only flash if you have an active network connection. The info light should come on if you press the small button in the bottom center of the rear fascia panel.

 

[Redcoat]

It occurs to me that you could look at this guide for the Mini https://forums.freenas.org/index.ph...and-mini-xl-motherboard-replacement-guide.53/
It has details and diagrams/photo's of the connections from the case to the MB - the case is essentially the same as yours at least from a front panel perspective, and the MB is the same from the point of view of headers.

 

[storage-junkie]

Oh - yes thank you! That guide is very useful! The reason I chose this hardware in the first place is because it was my understanding that it's the same components as are in the certified units from IX. I've looked at the closeup of the pin placement, and mine matches exactly. So I'm still not quite sure what's going on.

 

[Redcoat]

OK - how do you know the power switch works?

 

[storage-junkie]

Well, when I hit the power switch, the unit powers on. :)

 

[Redcoat]

If you've no indicator lights, what tells you that the mobo is powered? Do the fans run and the HDD's start?

 

[storage-junkie]

Oh yes - sorry, the unit fully powers up and I've already installed freenas at this point. It just would be nice to figure out why those front panel indicator lights aren't working properly. At this point, I'm wondering if there's some bios configuration that is disabling them maybe?

One thing that I did just get working was the front Info light. Going from the pictures in that guide you pointed me to, I saw that they had the OH LED wired up to one of the headers. When I wire that up, I see the info light turn on when I press the locator switch on the back of the MB now. So I know that THAT light works, at least.

 

[Redcoat]

Ahh - so it's operational, but not indicating. OK, so the ID light works.

What's left then is the power light, the lan activity light, and the hdd activity light. I'm still going to bet that the polarity is reversed. I suggest that you turn the plugs 180 degrees on the ones that are not working and see if that fixes it.

I have the C2750 and I have worked every item of every bios page and I am sure that there's no bios function that will inhibit those LED's.

 

[storage-junkie]

Yep - I just verified that as well. I went through literally every menu option in the bios, and there's nothing that controls that. The cables are color coded, but tried reversing them anyway, no go. I suppose it's possible there's a defect with those particular jumpers on this board.

 

[Redcoat]

I looked at the case manual in detail. The case is not quite the same as that used by iXsystems if the manual truly describes it. There's more intelligence in the interconnection between the backplane and the indicator lights, but what I could not tell is where the connections from the mobo come up to the backplane (and there's no description of the required cables). I was wondering how you used that header cable set that you bought ...

 

[storage-junkie]

Just confirmed the reset switch works, too :)

I just don't get it. I can IPMI into the console, power switch, reset switch and info light works, but pwr, hdd, and lan lights do not. (The hdd lights on the drive caddies themselves work fine.)

 

[storage-junkie]

just posted an image of the way I've got the wiring harness configured. I basically just came off the main ribbon from the front panel and plugged into it with the adapter that was included with the split cable kit. There's only one way the two can fit together, because there's a tab on the plug.

 

[Redcoat]

Well, next thing I would do is test the continuity of each of the 6 conductors in the three twisted pairs for those lights.

Off topic - where are you in KY - bad snow where you are?

 

[storage-junkie]

Yes, I thought it might be possible there was a break in some of the wires in the ribbon as it was crammed up pretty good inside the chassis when I first opened it. I'm in Louisville, and yes it's been extremely cold here since Friday. About 3-4" of snow currently. Good time to be messing with this kind of stuff!

 

[Redcoat]

There's only one way the two can fit together, because there's a tab on the plug.

Ahhh - my Mini case doesn't have that ribbon cable coming from the front - just individual twisted pairs coming down in a bundle leading to the mobo headers.

 

[storage-junkie]

Yeah, if Id have paid more attention to the cable I was buying I could have gotten a longer split cable and just used that. But I got a 6" split cable, so I had to attach it onto the end of the existing flat ribbon that's coming off the front panel.

 

[Redcoat]

My wife is at our place in Lexington now - was out shovelling snow today I guess.

I don't know what else to suggest on the LED front.