P5Q-Pro not restarting after changing BIOS settings

[I see SPY!]

Hello all.
I've been a visitor in this forum for some time, but unfortunately what made me register is a problem I'm having. For that, I apologize. I hope this is a good place to put the thread...

So, let me try to explain it as well as I can:

My computer is having a problem that prevents it from rebooting successfully.

Ever since I overclocked my cpu and changed some voltages in the bios to get it stable(vcore, pll,vtt, nb-all within safe values) I can use it as long as I'd like, but if I restart it I get only a black screen. The machine will still be on, the fans are spinning, but nothing shows on screen. I have to turn it off, disconnect the power cable and reset the cmos. Then, I turn it on and it will boot ok.

From what I've read in several places this is somewhat usual among those who have the p5q series. I tested almost all the settings inside the bios to find out which one is causing the problem and I am almost sure it is the "fsb termination voltage" option. If I set it to anything other than "auto", I won't be able to restart the pc. I have already reset the bios by removing the motherboard battery and resetting its options, and that didn't work. Am I missing something? Is it possible that a recent bios revision might help correct the problem, since I have a very old version?( mine is 0703, the most recent is 2100 something...)

I am a little concerned of touching the bios because something may go wrong, and then it'll be a PITA to RMA it.

I've also thought of leaving that particular setting in "auto", but after reading that the whole P5Q series overvolts like crazy, it leaves me a little bit uncomfortable. I really don't wanna fry my Wolfie
Check this out for reference. So, I want to overclock it a little bit, but in doing so the "auto" voltages MAY be all over the place. But if I set the values manually, the system gets unstable...
Oh, one more thing: I tried mailing Asus Support, and they've been as helpful as a kick in the teeth. Oh well

Thanks for the help.

[Mussels]

so what are you trying to do, get the OC stable, or get stock clocks to stop the black screen on reboot?

[I see SPY!]

Originally Posted by Mussels

so what are you trying to do, get the OC stable, or get stock clocks to stop the black screen on reboot?

Well, the OC is stable(at least stable enough for me) and it always had been working fine and dandy. The thing is, I started reading around that leaving these voltages in "auto" makes the mobo overvolt them, and I wanted to make sure they were within safer values. But in doing so I won't be able to reboot it. If I ever want to restart the machine, I'll have to power it off instead, then turn it on...

Oh, another thing: I don't believe this is a question of a unstable overclock, but rather some problem in the bios/bios chip. I've read on XtremeForum some guys complaining, and they also didn't manage to solve it...

So, in short(sometimes I tend to overdo on the explanations, sorry):

The overclock is fine, windows/games run good. But manually setting a voltage(which should be safe- 1.26 vtt instead of "auto") makes the machine not being able to reboot. Even if I up it to 1.28, 1.30, 1.32, it's a no go.

[[Ion]]

When the voltage are on auto, what does a program like CPU-Z or Everest report your voltage as. As long as it is below about 1.35, you will be perfectly safe

[I see SPY!]

Originally Posted by [Ion]

When the voltage are on auto, what does a program like CPU-Z or Everest report your voltage as. As long as it is below about 1.35, you will be perfectly safe

I suppose you're asking about the vcore? It's low, 1.18125. The problem is, I believe, the vtt. But there isn't any software that shows the vtt voltage, i think. I'll check Everest, though.

*EDIT*
Just checked Everest. I don't see any of those voltages listed.

[Mussels]

you sure its not northbridge or ram voltage?

i've seen boards where the voltages on reboot/restart are low for a few seconds, causing cold boot issues (but due to things 'warming up' they work fine on the next boot)

i havent had to mess with VTT at all on my board, so i think it may be something else.

[I see SPY!]

Originally Posted by Mussels

you sure its not northbridge or ram voltage?

i've seen boards where the voltages on reboot/restart are low for a few seconds, causing cold boot issues (but due to things 'warming up' they work fine on the next boot)

i havent had to mess with VTT at all on my board, so i think it may be something else.

For a while I thought that too, but I tried something just to be sure: removed the cmos battery to put everything back to stock. Then I went to the bios and changed only the vtt setting from "auto" to 1.26. Black screen upon restart. Then 1.28. Same thing. Then 1.30. Same.

So that's what makes me be so sure that it is only the vtt setting causing problems. I guess I'll have to keep it at auto...

Anyway thanks for the help. Maybe another P5Q user with a similar problem to this happens to see this thread

Black screen at boot means unstable overclock.

[Mussels]

i have a theory.

those lower VTT's may be default for other CPUs - the minimum may not be your default.

perhaps skip up, try 1.30-1.40 or something

The only time I ever get any blackscreens on boot is if Im either pushing my frequency too high or running it on too low voltage. Basically, the only things I change in my bios when overclocking are the multiplier, core frequency, ram speed, ram voltage and core voltage. I leave everything else to auto, and the NB / SB handle themselves all the way up to 4.05Ghz.

Try running the bios on the bare minimum, just tweaking what is absolutely necessary, see if that yields any luck.

[I see SPY!]

Originally Posted by Mussels

i have a theory.

those lower VTT's may be default for other CPUs - the minimum may not be your default.

perhaps skip up, try 1.30-1.40 or something

According to the manual, minimum value is 1.20 and it stays safe(BLUE) until 1.38. I'll try later to up it to 1.32 or more and see how it goes.

Originally Posted by kyle2020

The only time I ever get any blackscreens on boot is if Im either pushing my frequency too high or running it on too low voltage. Basically, the only things I change in my bios when overclocking are the multiplier, core frequency, ram speed, ram voltage and core voltage. I leave everything else to auto, and the NB / SB handle themselves all the way up to 4.05Ghz.

Try running the bios on the bare minimum, just tweaking what is absolutely necessary, see if that yields any luck.

Already did that(changing only the absolutely necessary, and everything works fine. It's just that option that's making me go nuts, because there shouldn't be a need for such a high vtt, but maybe my mobo/cpu just need that extra juice. I'll try it and see how it goes!

[Mussels]

there shouldnt be a need, in fact maybe its not related to VTT at all. maybe it can sit happily on auto, and its some other voltage you need tweaked.

we're going with VTT by your advice, when it may well be something else

[I see SPY!]

After you said that it could be unrelated to the vtt setting altogether, I tried something different: use a setting LOWER than what I had tried. And VOILA, it seems to be working fine at 1.20 vtt, when it didn't at 1.22, 1.24, 1.28.

That makes me think that:
-either the voltages that I've chosen result in some kind of voltage hole(maybe some bios bug?) OR
-setting the minimum value(1.20 is the minimum I can chose) actually does the same as auto(maybe doing some overvolting, such as the "auto" option).

Either way, I don't care anymore
I've obsessed about this long enough, and it seems to be working fine now, so... thanks for the help!