Should the PSU pwr up from inserting the 24 pin plug into the mobo?

[tireshark]

I'm in the middle of troubleshooting a faulty pc... im 90% sure it's the motherboard, but i have a question regarding the PSU.

I tested the PSU voltages with a multimeter, and they all seem to check out. i removed all cables from the motherboard (except for the case/heatsink fans) including usb and front panel pwr leads. When i connect the PSU to the motherboard using only the 24 pin connection, the PSU and fans power on (at max fan speed)... even though the front power switch is completely disconnected (there is no switch on the back of the PSU). Is this normal? Or is it more evidence of a faulty motherboard?

in case you're curious, the pc problem is: power up and get max fans, no beeps (even with ram removed), and no monitor signal. it had been an intermittent problem where i would get normal fans and no monitor... i could power cycle it 5-10 times and it would eventually boot up. recently it stopped booting up at all, in addition to constant max fans.

asus a8m2n-la motherboard

 

[ghnader hsmithot]

no, the mobo needs both 4/8 pin cpu connector and 24 pin mobo connector..

 

[tireshark]

eh... i think i didn't say it state my title clearly... what i meant to say is that the act of plugging the 24 pin connector to the mobo causes everything to power up. is that normal?

i know that you need the 4 pin connector for everything to function normally, and for the sake of this discussion, i can attach it to the motherboard as well. but i'm wondering if its normal for everything to power up as soon as i plug in the 24 pin connector, and without pressing any power buttons on the case or elsewhere.

 

[ghnader hsmithot]

no i dont think its possible.

If i am wrong then someone will correct me.However i dont think its possible.

 

[tireshark]

mmm.. well it is possible, because it is happening . i just dont know if it's normal or not... heh. i think it must be normal, because i tried it on another motherboard and the same thing happened. thx for responding, though.