CS-836TQ not powering up with HP MB - FIXED!

[Ray]

Compared to some problems listed this might be simple (or not).

I have an HP Z420 MB that I use for a backup server. It started life in a Z420 case so everything was fine. After about 5 years I needed more drives and got a PC case that I could load 8 dives in using a 3 into 5 and 2 into 3 frames with the SSD boot drives stuck to the bottom. That worked fine fo another 5 years and I moved up to a Supermicro CS836TQ. Like the chassis before it I needed a 24 to HP 16 pin adapter so I used my old one and I needed to extend the front panel wires. Like the server befoe, I only used Power Switch, Power LED and HDD LED on the HP header. That worked great all this time. Now it ,ostly doesn't work.

It seems that the Supermicro push button switch releases too fast or doesn't provide enough juice or something. I've disconnected the Power and HDD completely so all that goes to the header is the Power SW connector. Now given the placement of the header on the MB every time I want to connect the MB I have to pull the video card and one of the 2 HBAs to get my giant XXL hand in there. The server will usually start and boot FreeNas once just like it should. However, if I kill power to the server I have to go anjd disconnect the Power SW connector, reconnect it and put the cards back in and hope it will start again.

How I use this server is a bit odd so let me explain that so the collective genius out there has a better idea of what I'm doing. I backup on Sunday night so I couldn't see having this thing run even on minimal power for 6.5 days every week just waiting for me to backup stuff so I hooked it up to a wireless controlled wall plug. I turn on the plug, use WOL, do my backups, shut down the machine and turn off the power. Now that sounds awful lazy and it probably is but the backup is as physically far away from me as it can be and still be in the house. I'm on the 2nd floor right side front and the server is in the basement on the left side back corner.

I have an 846TQ (Intel MB) as my main unit so I popped out the power supplies and put them in the 836 - that didn't do anything. BTW. I turn the 846 on and off the same way as I want to do with the 836 and it works every time. I left the video card and HBA out after unconnecting and reconnecting the power switch sometime that worked sometimes it didn't. I hooked up a 450W power supply to the MB while it was still in the 836 chassis and that didn't work. I took it out of the 836 and put it back in the old chassis and it worked fine. One of the options on the MB is to power on after a power failure which is how I have been using it. I set it to remain off after losing ppwer to see if I could turn it on manualy and that didn't work After the very first time I push the 836 ON button after reapplying power I do get a little beep and the CPU fan moves slightly . If the CPU fan continues to move I know the server will start but that isn't the norm at the moment.

I'm thinking that it might be the Power Distribution board because it is one of the few things I haven't chacked but I really don't want to rip my main server apart without a better reason than a hunch. So anybody got any ideas?

Thanks for reading.

 

[Markess]

Could be something is grounding out in the case.

Have you pulled the motherboard and made sure there isn't a rogue standoff in the wrong place? Maybe something left over from the previously occupying motherboard? The Z420 board is missing some mounting holes where an ATX/MATX/EATX board would have them, and has some holes where the others wouldn't.

Can you fit a long bladed screw driver in to short across the power switch pins on the motherboard with the chassis power switch disconnected? If you can reliably start the server with a screwdriver (or other long thin metal thing that will fit) then its probably a bad power switch or lead.

 

[Ray]

Could be something is grounding out in the case.

Have you pulled the motherboard and made sure there isn't a rogue standoff in the wrong place? Maybe something left over from the previously occupying motherboard? The Z420 board is missing some mounting holes where an ATX/MATX/EATX board would have them, and has some holes where the others wouldn't.

Can you fit a long bladed screw driver in to short across the power switch pins on the motherboard with the chassis power switch disconnected? If you can reliably start the server with a screwdriver (or other long thin metal thing that will fit) then its probably a bad power switch or lead.

Let me disconnect the MB from the chassis and see what that does. I know about the different standoff heights and only used ones that came with the server. There is on MB hole that doesn't match any standoff so that is empty otherwise everything else is the correct height and location

 

[Markess]

That's a good idea. Since everything worked in a different chassis, and you tried a second known good power supply with the motherboard board in this chassis without consistent success, then either something broke with the motherboard during the transfer, or there's something wrong with the chassis itself. Since that second power supply would have bypassed the PDB, I think a bad PDB is unlikely.

I'd think the most likely issue is a bad power switch or something electrical involving the chassis itself. Did you try starting with power and cabling to the backplane disconnected? You wouldn't be able to boot up all the way without drives, but if it got through post regularly with the backplane isolated, that would be an indicator of a backplane problem.

 

[Ray]

Well I'd love to claim that my superior troubleshooting skills solved the problem but that isn't the case. I pulled the MB and had it sitting on a piece of wood when I hooked everything back up and it worked as intended. I then put it back in the 836 and put in one card (video) and it didn't work. I then thought there might be some minor strain on the MB that opened up a solder run so I started to unscrew the screws holding the MB to the stanchions one at a time. Took all 9 out testing after each one and it still would boot the way is used to. I then decided to put all the screw back in and this time start at the back to remove them and see what happens. The frist 2 did nothing but after taking out #3 it worked. In fact if I used any of the 3 holes across the back it didn't work. So now I only use 6 screws to hold down the MB and everything is as it was.

I still don't know exactly what the problem was and I really don't care since the next time that MB comes out it will be for and upgrade.