Hi 👋
I think you can easily check the AT power connector, if you use an ATX power supply, you will need an AT ATX adapter, just check the wires of the +5V +12V voltages and those of the -5V and -12V, with an ohm tester you can check if the voltage pin leads to the ISA slot, if they match the PIN-OUT of the ISA slot, you can check the black wires if they go to ground, if so, there is only one wire left that of the PowerGood, obviously 🙄 it will not be necessary to do anything else, however it is possible that the PIN-OUT of the power connector can be found in the manual.
Possibly if you have further doubts, before trying, I suggest you show here what you have found, rather than trying to turn on the power supply, but it is very likely that the PIN-OUT is not proprietary.

PC@LIVE wrote on 2025-12-05, 20:15:

Hi 👋
I think you can easily check the AT power connector, if you use an ATX power supply, you will need an AT ATX adapter, just check the wires of the +5V +12V voltages and those of the -5V and -12V, with an ohm tester you can check if the voltage pin leads to the ISA slot, if they match the PIN-OUT of the ISA slot, you can check the black wires if they go to ground, if so, there is only one wire left that of the PowerGood, obviously 🙄 it will not be necessary to do anything else, however it is possible that the PIN-OUT of the power connector can be found in the manual.
Possibly if you have further doubts, before trying, I suggest you show here what you have found, rather than trying to turn on the power supply, but it is very likely that the PIN-OUT is not proprietary.

Hi!
I connected this board to a standard AT PSU, and my post card shows all power led status high, but ready and reset signal is low. Seems like an issue with 82371fb chipset, because it generates global reset signal, maybe this board requires extra power management by PS_ON connector. Power On switch not affecting anything. So, will try to double check everything around the chipset.

Kepler386 wrote on 2025-12-06, 02:06:

PC@LIVE wrote on 2025-12-05, 20:15:

Hi 👋
I think you can easily check the AT power connector, if you use an ATX power supply, you will need an AT ATX adapter, just check the wires of the +5V +12V voltages and those of the -5V and -12V, with an ohm tester you can check if the voltage pin leads to the ISA slot, if they match the PIN-OUT of the ISA slot, you can check the black wires if they go to ground, if so, there is only one wire left that of the PowerGood, obviously 🙄 it will not be necessary to do anything else, however it is possible that the PIN-OUT of the power connector can be found in the manual.
Possibly if you have further doubts, before trying, I suggest you show here what you have found, rather than trying to turn on the power supply, but it is very likely that the PIN-OUT is not proprietary.

Hi!
I connected this board to a standard AT PSU, and my post card shows all power led status high, but ready and reset signal is low. Seems like an issue with 82371fb chipset, because it generates global reset signal, maybe this board requires extra power management by PS_ON connector. Power On switch not affecting anything. So, will try to double check everything around the chipset.

Hi 👋
Well I imagined that an AT power supply would have started the motherboard, but if I understood correctly, you have in the post card the RESET LED always on, while usually it should turn on and off (quickly), maybe if you can add a photo of the post card with the LEDs on, it would be useful.
I don't think there's a need for extra voltage, and I don't think there's any pin on the MB for the PS_ON, it should be a normal motherboard in LPX format, a particular format for desktop cases with reduced height.

Hi,
The cooler are working. No information on my post-card. No video signal. VRM vltage 3.5V. Vcc2, Vcc3 voltage on CPU socket - 3.5v. I attached photos of this board and post-card information. I have two same boards with the same behavior 😀
Maybe I'm doing something wrong to make it alove, or this board with the problems.
Thank you for any information!

Kepler386 wrote on 2025-12-06, 08:00:

Hi, The cooler are working. No information on my post-card. No video signal. VRM vltage 3.5V. Vcc2, Vcc3 voltage on CPU socket […]
Show full quote

Hi,
The cooler are working. No information on my post-card. No video signal. VRM vltage 3.5V. Vcc2, Vcc3 voltage on CPU socket - 3.5v. I attached photos of this board and post-card information. I have two same boards with the same behavior 😀
Maybe I'm doing something wrong to make it alove, or this board with the problems.
Thank you for any information!

Looking at the last photo, I can tell you that the power is fine, it doesn't start because you use only one RAM bank, add the second one, and you'll see that it works, of course you have to be sure that both the RAM and the CPU work, but in the meantime try with two RAMs, and let us know if it works, or if something changes.

Have you tried asking this guy ? He has a few videos using a Siemens-Nixdorf Scenic Pro C5

https://www.youtube.com/watch?v=ZWHZYNcZskE

also, make sure the cr2032 is replaced with a good one.
also2, the power switch seems to be of the latching kind, not the momentary push button kind.

Kepler386 wrote on 2025-12-04, 20:17:

Hello folks, […]
Show full quote

Hello folks,

Does anyone know if it’s possible to power on this board with a standard AT power supply?
Or does it require some special tricks? Or I need an original power supply?

Same board here: https://theretroweb.com/motherboards/s/siemen … stem-board-d943

Thanks!

weedeewee wrote on 2025-12-06, 11:26:

Have you tried asking this guy ? He has a few videos using a Siemens-Nixdorf Scenic Pro C5 […]
Show full quote

Have you tried asking this guy ? He has a few videos using a Siemens-Nixdorf Scenic Pro C5

https://www.youtube.com/watch?v=ZWHZYNcZskE

also, make sure the cr2032 is replaced with a good one.
also2, the power switch seems to be of the latching kind, not the momentary push button kind.

Kepler386 wrote on 2025-12-04, 20:17:

Hello folks, […]
Show full quote

Hello folks,

Does anyone know if it’s possible to power on this board with a standard AT power supply?
Or does it require some special tricks? Or I need an original power supply?

Same board here: https://theretroweb.com/motherboards/s/siemen … stem-board-d943

Thanks!

Actually looking at the photos, the writing PS_ON refers to the AT connector, while the three-PIN one is CD, I hope 🤞 it has not been powered, however the proximity of the writing can raise doubt.

Kepler386 wrote on 2025-12-06, 08:00:

Hi, The cooler are working. No information on my post-card. No video signal. VRM vltage 3.5V. Vcc2, Vcc3 voltage on CPU socket […]
Show full quote

Hi,
The cooler are working. No information on my post-card. No video signal. VRM vltage 3.5V. Vcc2, Vcc3 voltage on CPU socket - 3.5v. I attached photos of this board and post-card information. I have two same boards with the same behavior 😀
Maybe I'm doing something wrong to make it alove, or this board with the problems.
Thank you for any information!

Thanks to the video of "weedeewee", I saw that next to the RAM near the LED connectors, there is a 2 PIN Power Switch connector, here I don't know if it's a switch or a button, I would try the button first, if it doesn't start try the switch, I think this is enough to start the motherboard.

weedeewee wrote on 2025-12-06, 11:26:

Have you tried asking this guy ? He has a few videos using a Siemens-Nixdorf Scenic Pro C5 […]
Show full quote

Have you tried asking this guy ? He has a few videos using a Siemens-Nixdorf Scenic Pro C5

https://www.youtube.com/watch?v=ZWHZYNcZskE

also, make sure the cr2032 is replaced with a good one.
also2, the power switch seems to be of the latching kind, not the momentary push button kind.

Kepler386 wrote on 2025-12-04, 20:17:

Hello folks, […]
Show full quote

Hello folks,

Does anyone know if it’s possible to power on this board with a standard AT power supply?
Or does it require some special tricks? Or I need an original power supply?

Same board here: https://theretroweb.com/motherboards/s/siemen … stem-board-d943

Thanks!

Looking better I have to correct myself, sorry but the three-pin one is a connector for the Soft PWR_ON, the one for CD is a predisposition.
In short, it is a bit of a peculiar card, it looks like an ATX power supply with an AT connector, and without the +3.3V.

PC@LIVE wrote on 2025-12-06, 12:42:

weedeewee wrote on 2025-12-06, 11:26:

Have you tried asking this guy ? He has a few videos using a Siemens-Nixdorf Scenic Pro C5 […]
Show full quote

Have you tried asking this guy ? He has a few videos using a Siemens-Nixdorf Scenic Pro C5

https://www.youtube.com/watch?v=ZWHZYNcZskE

also, make sure the cr2032 is replaced with a good one.
also2, the power switch seems to be of the latching kind, not the momentary push button kind.

Kepler386 wrote on 2025-12-04, 20:17:

Hello folks, […]
Show full quote

Hello folks,

Does anyone know if it’s possible to power on this board with a standard AT power supply?
Or does it require some special tricks? Or I need an original power supply?

Same board here: https://theretroweb.com/motherboards/s/siemen … stem-board-d943

Thanks!

Looking better I have to correct myself, sorry but the three-pin one is a connector for the Soft PWR_ON, the one for CD is a predisposition.
In short, it is a bit of a peculiar card, it looks like an ATX power supply with an AT connector, and without the +3.3V.

Please stop making so many posts. Kepler386 already mentioned once trying the power switch.
You adding three comments just to add something you noticed is making this thread bloated.