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P5B Deluxe - dual power on every boot

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Buckster

Registered
Joined
Sep 7, 2006
How many other people are getting the dual power on when booting ?

At 330fsb, with old bios, if I turned on PC normally, no dual power on (dual power on as in, power goes on for about 1 second or less, then powers off, stays off for about 1 second, then repowers on and boots and posts perfectly), when powered on normally, but did dual power-on if I turned off at wall or changed a bios setting.

Now with new bios, and at 345 fsb, every time I power on the PC or even restart windows it does the double power on.

Doesn't do any harm, just wondered why it did it ?

I have a hunch it could be to do with auto-voltages but I'm not sure ? almost as if the first power on is almost a test to see if voltages high enough

any ideas ?

thanks, Mark.
 
This is absolutely normal when overclocking this motherboard. I think all of us experience this issue. You have no idea what a PITA it was for me with a Vapochill Phase unit. Everytime the motherboard switched off power on the double boot it would turn off my phase change unit as well. I had to make custom switches, jump a secondary PSU and bypass the chill control unit completely in order to run the phase change seperately from the rig. :bang head

Anyway, back to the issue at hand. This is coming directly from Asus:
Originally Posted by eva2000
Actually, I got a reply from an Asus contact about the auto power down and power up function on P5W DH if it's same as P5B DX:

Quote:
This behaviour is caused by system's limitation. For over-clocking, the
internal PLL of NB would not lock on the high clock right away, so that means
system could not hold on the clock frequency immediately after reset. That's
why we add a auto-power down scheme to fix this issue. Of course, this
behaviour only occurs at over-clocking scenario.
 
That does sound a pain in the neck Dominick.

Thanks for the reply - I'm glad the double power on is normal - was worried I was damaging something.

cheers, Mark.
 
see this is what I don't understand. Not all boards do this, and still overclock as good as the P5B Et al. So why doesn't Asus just fix it so that it doesn't do this
 
Dang... nice O/C (as he removes his foot from his mouth lol)

Unless I'm mis-reading the first post... he's talking about the normal abnormality with these boards. When overclocked beyond about 30% from memory, you press the power button to power up... the computer bursts into life for a second or so, dies for a few seconds, then restarts all by it's little self and behaves perfectly normally from then until the next startup, when it will do exactly the same thing.

If you don't have this, then we all want to know why not!
 
Ya got same issue its annoying. While its normal I find more comforting but still thats double the power on for HDD's, Graphics, CPU, DVD drive. That can't be good for them.
 
deathman20 said:
Ya got same issue its annoying. While its normal I find more comforting but still thats double the power on for HDD's, Graphics, CPU, DVD drive. That can't be good for them.

i second that. its more on the hd especially on cold boots.
 
I shouldn't have said anything... Now mine is doing the dual boot..LOL. Just another reason to leave it on.

BTW, I did take off the nb cover and put a small fan on it, boosted the nbvoltage, and got to 440.. More testing later.
 
This has something to do with the MB itself. The P5W-DH does the same thing. Check out these videos (pretty bad quality :( ) I made. It shows the 12V line going to zero.:-
http://www.zippyvideos.com/1624907415705816/mvi_0048/
http://www.zippyvideos.com/6721264985710946/mvi_0544/*snocforums
http://www.zippyvideos.com/9712911875710986/mvi_0546/*snocforums

Put one prong of the DMM in the slot with green wire of the PSU ATX connector and another one in the Black wire's slot. This will tell you if the PS_ON signal (a sense pulse which turns the PSU/ON or OFF) is sent. If you see a reading of 5 V briefly, then the PSU has completely shut down and restarted.

There is nothing wrong with either the PSU or MB.
 
Thanks for all the responses

and fritzman - thanks for the friendly welcome :)

Mark.
 
Any updates on this issue? I can't understand why the board is behaving like this on cold boot events? My good old P5WD2 did this on warm restarts over ~240MHz FSB. This is something I could live with.

Perhaps it can be fixed by fixing the PCIe frequency to 96MHz...
 
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