Can't get any LED to light on my Supermicro M11SDV-8C-LN4F

k4J768

New Member
Jun 24, 2022
9
2
3
I've purchased a Supermicro M11SDV-8C-LN4F and tried to power it with my long-living be quiet! Dark Power Pro 10 550W power supply, however I can't get any LED on the mainboard to light up.
The PSU is working fine (and even is now) when I connect it to an old ASRock Rack C2750D4I using its onboard 24-pin ATX plug.
The LEDs on the Supermicro board light up when I connect another power supply that I borrowed from a friend.

The Supermicro board has an ATX to 4-pin adapter (CBL-PWEX-1063) that should power the mainboard, however it doesn't seem to work.
The manual of the Supermicro board mentions that it needs "ATX power supply Specification 2.02 or above", while the PSU has "Intel ATX12V Power Supply Design Guide Version 2.31 (and downwardly compatible to V2.3, V2.2, V2.01, V2.0 )".

Any ideas?
 

k4J768

New Member
Jun 24, 2022
9
2
3
Yes, the 8pin connector is also connected.
However, I am not sure if this is already necessary, as absolutely no LED lights up (the mainboard's power LED lights up when I connect it to my friend's power supply, even without the 8pin connector).
 

i386

Well-Known Member
Mar 18, 2016
3,123
998
113
33
Germany
my interpretation from a quick google search and supermicro faqs is that you need the 8 pin connector for powering the mainboard + cpu and the 4 pin connector for starting the system via a power button (supermicro mentions in the faqs for x12 board that it's possible to start a system by shorting certain pin on the 20/24 pin connector from the psu)
 

k4J768

New Member
Jun 24, 2022
9
2
3
That would make perfect sense, but the mainboard still has no power even if the 8-pin connector is connected correctly.
Does anything have to be triggered on the power supply to get power to the 8-pin connector? Measuring the 8-pin connector with a multimeter shows no voltage at all.
 

RolloZ170

Well-Known Member
Apr 24, 2016
1,834
468
83
55
Does anything have to be triggered on the power supply to get power to the 8-pin connector?
yes the PS-ON pulled to ground.
the 8 Pin is +12V. without PS-ON only +5VSB is there.
there is also a PWR-OK signal in the 4 pin
 

RolloZ170

Well-Known Member
Apr 24, 2016
1,834
468
83
55
and with only the 4 pin +5VSB (standby) poweres the BMC, a led should be flashing after some time (BMC heartbeat LED)
 

RolloZ170

Well-Known Member
Apr 24, 2016
1,834
468
83
55
by the way. some Modular PSU need shortings for feedback sense signals. maybe the adapter 4 <->24 Pin is the issue.
tried a non Modular PSU ?
 

k4J768

New Member
Jun 24, 2022
9
2
3
yes the PS-ON pulled to ground.
the 8 Pin is +12V. without PS-ON only +5VSB is there.
there is also a PWR-OK signal in the 4 pin
But doesn't the PS-ON only need to be pulled to ground when I actually want to start the system / boot the BIOS? Note that currently there isn't any LED lighting up in powered-off mode. I expect at least the BMC to power on after some time (which it doesnt even after 30 minutes)
 

k4J768

New Member
Jun 24, 2022
9
2
3
by the way. some Modular PSU need shortings for feedback sense signals. maybe the adapter 4 <->24 Pin is the issue.
tried a non Modular PSU ?
My friend's PSU is also modular and it works fine with it.
I could of course buy the exact same PSU from the local hardware shop. But since I know that the power supply works well, I don't want to throw it away.
 

RolloZ170

Well-Known Member
Apr 24, 2016
1,834
468
83
55
My friend's PSU is also modular and it works fine with it.
some work some not.
But doesn't the PS-ON only need to be pulled to ground when I actually want to start the system / boot the BIOS?
the system pulls this signal down(then the PSU gives all other Voltage) by power on switch or WOL / power on keyboard/mouse event.
maybe the PWR-OK signal of your Bequiet is bad. PWR-OK is valid after power on, not standby.
 

RolloZ170

Well-Known Member
Apr 24, 2016
1,834
468
83
55
I could of course buy the exact same PSU from the local hardware shop
check if the ground cable connects to a ground on the 24pin PSU.
but at least with the 8 pin there must be enough ground, do you use the EPS cable or (wrong) GPU ?
 

k4J768

New Member
Jun 24, 2022
9
2
3
check if the ground cable connects to a ground on the 24pin PSU.
but at least with the 8 pin there must be enough ground, do you use the EPS cable or (wrong) GPU ?
I'm sorry, what is meant with ground cable?
I'm plugging the 8 pin cable to the "P8/P4" socket as shown below. The other end ("CPU1-P4" and "CPU2-P8") goes into the socket on the mainboard. Is that wrong?
 

RolloZ170

Well-Known Member
Apr 24, 2016
1,834
468
83
55
I'm sorry, what is meant with ground cable?
there is only one ground connection in the 4 pin from the mobo to the PSU. if this is on the (right) wrong place nothing work.
notmaly the 24pin is connected to a motherboard and all ground pins are shorted together.
but with the 8 pin there are 4 more ground connections.
i think the +5VSB power of the BeQuiet is not enough (can be from old caps, for old motherboards its may still work)
 

i386

Well-Known Member
Mar 18, 2016
3,123
998
113
33
Germany
Same PSU model or a differrnt one? (For the people in the Future comming from Google)
 

RolloZ170

Well-Known Member
Apr 24, 2016
1,834
468
83
55
Same PSU model or a differrnt one? (For the people in the Future comming from Google)
i bet the good old PSU was not able to deliver enough +5VSB power.
Note: old non server intel motherboards don't draw much standby power., but here the BMC and the chipset is powered by +5VSB, need at least 3 Amps or more. Additionaly, the electrolyt of the Capacitors(standby circuit) getting dry over time.
 
  • Like
Reactions: k4J768

i386

Well-Known Member
Mar 18, 2016
3,123
998
113
33
Germany
be quiet dark power 12 1000watt psu + supermicro m12swa-tf seems to be problematic too. The bmc led blinks but nothing else happens.