disable the CPU,but keeping it as a powersupply

[hjwinge]

Hi I just got the probox, and it works great, with my cubase 8 pro.

Like most others, I think the cpu is too noisy. I have in a forum been told I can just unplug the motherboard in the big box to shut off the fan. I dont need any audio or the D8B software, I use it only as a DAW controller.

Can I open the box and unhook all the computer cables and only use the big cable from the box to the d8b as a powercable without breaking anything? Will I loose the fan-noise as I hope? I would rather not do any other modifications inside the CPU.

hj

[bitSync]

You can disconnect power to the mainboard and that will disable everything on it to include the noisy CPU fan. You will still have the fan noise from the stock AT power supply.

Or you could do this...

http://www.d8bforum.com/phpBB3/viewtopic.php?f=2&t=1175&p=9166&hilit=silent#p9166

Best of luck.

[bitSync]

Also, some folks have built dedicated standalone fanless power supplies. You'll have to search the forums here.

[hjwinge]

Hi, thank you for replying!

I unplugged both powercables on the motherboard, and by doing this the fan on the power supply stopped as well. This made the unit completly silent, and when i booted the d8b with the probox, it seemed to work.

Very happy I closed the box thinking this was brilliant, but when i tried to reboot again the probox always hanged on the loading firmware. In the end I had to open the CPUbox again and reconnected ONE powercable on the motherboard (to the powersupply, I think). This started the fan again and the probox worked as normal, but with the fannoise back.

Im not a PCbuilder or electrician, but I would assume that the D8B only need the power from the CPU, not any actually data signal when I have connected the probox.

By disconnecting both powercables on the motherboard, and with this stopping the noisy powerfan, also mean that the D8B doesnt get enough power? Or does the D8B still need some data from the motherboard to boot right? Why didnt the probox work without the CPU motherboard connected??

Hope someone can explain!
(really like the probox!!)

[bitSync]

Hi, thank you for replying!

I unplugged both powercables on the motherboard, and by doing this the fan on the power supply stopped as well. This made the unit completly silent, and when i booted the d8b with the probox, it seemed to work.

Well, this also means that (1) the AT power supply, which is meant to be cooled by the fan in the AT power supply, now has no fan to cool it and you run the risk of the AT power supply overheating and causing some damage, and (2) the fan in the AT power supply is also used to draw air through the front of the chassis across the other power supply components and they are likely to overheat with no airflow and with a sealed cover. This is why I installed a fanless ATX power supply in my modification and opened up the chassis cover to allow convection cooling.

Was the system already up and running when you disconnected the motherboard power connectors from the AT power supply? Did you shutdown then restart now with no power to the mainboard?

Very happy I closed the box thinking this was brilliant, but when i tried to reboot again the probox always hanged on the loading firmware. In the end I had to open the CPUbox again and reconnected ONE powercable on the motherboard (to the powersupply, I think). This started the fan again and the probox worked as normal, but with the fannoise back.

I don't have the AT power supply cable pinout in front of me but it sounds like without one of the connections onto the mother board the AT power supply is at least partially if not completely disabled. I'll have to consult my notes. The d8b control surface needs all of its voltages to function properly. If one or more of the required voltages are not present it's likely the control surface won't interact properly with the ProBox USB communications.

[hjwinge]

Hi, the system was not running when I unplugged inside. (or replugged).

I think you are right about the voltage.

About the heat, I would think that since the motherboard is not connected anymore, it would not be any heat issues on that part. However, even when I had unplugged both wires there was still a small fan ontop of the motherboard still working. Since I just bought the D8B, I wonder if this is due to a modification from the previous owner? This fan is almost complety silent.

Thanks for taking the time to answer!

[munkustrap]

Hi
so it might work with the disabled fan in the PSU, but it may fail. As Explanation:

the 12V drives the Motor faders (and some other stuff but that is less and we do not care about that).
the current consumption of the 12V depends on the Motor moves. So many moves means much current.
It depends if you drive one fader or 24 faders in Automation. E.g. if you have 24 faders moving for 5 seconds it will be critical for your supply without fan.

maybe you check for a fanless CPU power supply ? you Need 8A on 12V

best regards
Munk

[bitSync]

From the d8b database, here's a look at the voltages coming into the control surface at the console power distribution board 111.

http://www.sonido-7.com/d8b/files/d8bservice/111b.pdf

[rutah213]

I just converted mine over to a silent power supply (no cpu) with a $20 power supply that I bought on eBay. Ralph was amazing walking me through the process as the description was not detailed enough for me. I'd be happy to help as I now have a full understanding of this process.

[munkustrap]

Thanks rutah213

I never made a CPU fanless, my documentation is only based on my electronic knowledge so I've overseen the "small" Detail that only one of the two black GND lines is connected.
So everybody that wants to replayce the CPU powersupply by a fanless 12V supply take care that you use the black wire beside the yellow one and not the black beside the red one.

I will do such a modification in the next weeks for a customer, then I will be able to take Pictures and my deliver a more detailed and clear documentation of this.

best regards
Ralph/Munk