NF4 Expert will not cold boot- psu issue?

[BigKohones]

Was toying with memory settings, had been running stable at DDR500 (250Mhz) 3-3-3-5@1T; tried to tweak it to 2.5-3-3-5@1T and the PC will not boot. Stuck at 4 LEDs. Tried clearing CMOS, Safe Boot, unpluged for hours..no luck. The ram sticks work in my P4 stick..can you fry the board by adjusting memory timing?

[red930]

Try this...

http://www.dfi-street.com/forum/showpost.p...04&postcount=24

 

Was toying with memory settings, had been running stable at DDR500 (250Mhz) 3-3-3-5@1T; tried to tweak it to 2.5-3-3-5@1T and the PC will not boot. Stuck at 4 LEDs. Tried clearing CMOS, Safe Boot, unpluged for hours..no luck. The ram sticks work in my P4 stick..can you fry the board by adjusting memory timing?

[fiberoptik]

The power switch on an ATX power supply is simply a dead short between two points.

 

Here's a little test.

 

Remove the leads from the ATX connector and short them outside of the connector and you get the very same results.

 

This is why you can add the capacitor at the connector or inside the power supply and the mod still works.

 

For clarity.

------

3.3.2. PS_ON#

PS_ON# is an active-low, TTL-compatible signal that allows a motherboard to remotely control the power supply in conjunction with features such as soft on/off, Wake on LAN*, or wake-on-modem. When PS_ON# is pulled to TTL low, the power supply should turn on the four main DC output rails: +12VDC, +5VDC, +3.3VDC and -12VDC. When PS_ON# is pulled to TTL high or open-circuited, the DC output rails should not deliver current and should be held at zero potential with respect to ground. PS_ON# has no effect on the +5VSB output, which is always enabled whenever the AC power is present. Table 16. lists PS_ON# signal characteristics.

 

The power supply shall provide an internal pull-up to TTL high. The power supply shall also provide de-bounce circuitry on PS_ON# to prevent it from oscillating on/off at startup when activated by a mechanical switch. The DC output enable circuitry must be SELVcompliant.

 

The power supply shall not latch into a shutdown state when PS_ON# is driven active by pulses between 10ms to 100ms during the decay of the power rails.

------

I hope that resolves any other questions regarding the source of this issue.

 

Once more for clarity.

 

It is not the motherboard or the BIOS.

 

The power supply is not "latching" to the "Power On" signal. The BIOS can not have an effect on a mechanical connection.

 

This is why you can reproduce the symptom without a motherboard attached to the power supply.

 

I'm not sure how to make this any more clear than I have already.

 

For the very last time.

 

If you have a power supply that won't work with your DFI board you have two choices. Replace the motherboard or replace the power supply.

 

Roadie then please explain to me how my system booted flawlessly with a capacitor with an old version of bios used on nf4 sli-dr boards and now fails while using the Expert Bios???

[red930]

Roadie then please explain to me how my system booted flawlessly with a capacitor with an old version of bios used on nf4 sli-dr boards and now fails while using the Expert Bios???

The BIOS is corrupted.

[scottR]

Figured I'd chime back in now that my Expert board has come back from rma.

 

Result:

 

Same issue, no boot after proper shutdown from windows or power off with the case switch. No explanation came with the board on arrival back from rma. Same board, serial numbers match. Perhaps all that was done is put in a new bios chip, seems to have a gold or yellow dot on one corner. For all I know the board was tested and shipped right back.

 

I also rma-ed my psu to OCZ and they sent a nice 600w in place of the 520w. If this problem is directly related to power supply startup voltage variance then why the heck is OCZ the number 1 recommended psu for this board? That recommendation is the sole reason I purchased an OCZ psu and it is posted prominently on this site.

 

Interestingly enough my board is also a revision AA0.

 

What next, just learn to live with it?

[RGone]

Thanks "scottR" for letting us know where you stand now.

 

"scottR" are you in the US? Had to 'submit' so I could get out and see your location. Yep you are in TX. I know you are in a dilemna of sorts and I do NOT know all the answers yet, hale may never. But this supply is what I am running right this minute. I mention it because it is nearly cheap enough to buy it and try it and get you out of your situation, if you should choose to do while all this is going on. I am using AB0 board that for me "began" by cold booting until I ran it few days and swapped over to this cheaper supply. My guess is that the cheaper units that seem to beat the premier units have a "lesser'' OCP circuit. The higher dollar units have better OCP and shutdown when current is drawn at startup.

 

Now again 'scottR' and it really is to you man, I am just before shutting down and swapping to a 7 month old OCZ 600 PowerStream and will report back my findings. I am not picking on you man but I can only monitor well one situation at a time and I know your board has 'gone' and come back and I know where you are. So I am only speaking more or less to you at this time. Got it? Thanks man.

 

RGone...

 

Figured I'd chime back in now that my Expert board has come back from rma.

 

Result:

 

Same issue, no boot after proper shutdown from windows or power off with the case switch. No explanation came with the board on arrival back from rma. Same board, serial numbers match. Perhaps all that was done is put in a new bios chip, seems to have a gold or yellow dot on one corner. For all I know the board was tested and shipped right back.

 

I also rma-ed my psu to OCZ and they sent a nice 600w in place of the 520w. If this problem is directly related to power supply startup voltage variance then why the heck is OCZ the number 1 recommended psu for this board? That recommendation is the sole reason I purchased an OCZ psu and it is posted prominently on this site.

 

Interestingly enough my board is also a revision AA0.

 

What next, just learn to live with it?

[Alex**]

oh i hope mine doesnt come back without it fixed

[scottR]

Hey RGone, I hear ya. I've already tried a cheaper psu model (Raidmax) on this board and it worked fine (in other words no cold boot issue). Unfortunately it did not have all the proper connectors for the board (1/2 of the 8 pin connector- aka P4, no pcie conector) and was not stout enough (~400w) to run all my hardware and have any margin for error, otherwise I would be using it! My rma request for the board was out of frustration thinking it had to be something on the board...maybe not. I ran this board for at least two weeks after purchase before I broke down and got the rma authorization (this build was started right before Christmas).

 

I work in the industry (since 1995) and fix computers nearly every day so this is not new territory for me. My beef is popping ~$150 for a sweet OCZ psu only to find it does not work properly out of the box with this board even after all the acclaim and hoopla associated with it. Since I rma-ed the original 520w one to OCZ I cannot return the 600w they sent me to the original vendor for credit or refund- so I'm either stuck with it, sell it on epay for a loss or keep it around in case I build something else that it plays nicely with.

 

I'm interested to find out your results...let us all know!

[ISSA2000]

Roadie then please explain to me how my system booted flawlessly with a capacitor with an old version of bios used on nf4 sli-dr boards and now fails while using the Expert Bios???

 

 

i have a sintek 600w sli power supply

http://www.sin-tek.com/sintek-products-sintek600sli.htm

i was told it would work with expert board.

 

my cold boot problem unless you rapidly press the power/on-off - you cant turn the computer on 99% time, :shake:

 

gave the .22uf cap a go (connected via front button of case)

and now 95% time it works :angel: (every once in a while it will turn on for 4 seconds then turn off (it will do that repet till you turn psu off then on).

 

but if i did not try .22uf cap i would have sent my board back for warrenty :confused: , as

psu is 3 months old working on a asus board a8v deluex +4800

 

now is my board faulty- or is it an compattibility prob.

its 3 days old. i could return it /or swap it for another board-maker - no cost exp postage?

i do like the board -except for cpu placement (problem with small case + rhdd bracket+cables)

 

would a 1000uf cap be better?

 

i dont care whos at fault, just to fix it with my psu (i love my psu) 34a 12v passive correction true 600w) runs at 42dcel

[RGone]

'scottR' got severely side-tracked man. Digging and scratching and checking around. I think there is some sort of problem with the +5VStndby. It appears that a couple of power supply companies and DFI are now testing and as with any large corporate situation will probably be a week to 10 days before they can decide what it is needs to happen. I had forgot the size and speed of corporate wheels when I began to back-track and double-check today. So it looks will be some longer before I can hear from the engineers that are looking into this now. No sense in me beating my head since they are doing the looking now. Hang on if you can.

 

RGone...

 

Hey RGone, I hear ya. I've already tried a cheaper psu model (Raidmax) on this board and it worked fine (in other words no cold boot issue). Unfortunately it did not have all the proper connectors for the board (1/2 of the 8 pin connector- aka P4, no pcie conector) and was not stout enough (~400w) to run all my hardware and have any margin for error, otherwise I would be using it! My rma request for the board was out of frustration thinking it had to be something on the board...maybe not. I ran this board for at least two weeks after purchase before I broke down and got the rma authorization (this build was started right before Christmas).

 

I work in the industry (since 1995) and fix computers nearly every day so this is not new territory for me. My beef is popping ~$150 for a sweet OCZ psu only to find it does not work properly out of the box with this board even after all the acclaim and hoopla associated with it. Since I rma-ed the original 520w one to OCZ I cannot return the 600w they sent me to the original vendor for credit or refund- so I'm either stuck with it, sell it on epay for a loss or keep it around in case I build something else that it plays nicely with.

 

I'm interested to find out your results...let us all know!

[biohazrd]

I have a PC Power and Cooling T51ASL ATX P/S (24 +8 pin) and have the same problems with not being able to do a cold reboot. I don't have an OS installed as I was trying to configure the bios due to my case not having a reset switch. I wanted to make sure everything worked for power on and power off.

 

After manually turning the power off with the switch it will not power back up, unless I turn the P/S power switch off for a moment and then back on. I was able to pull the ATX switch from the header on the MB and use the built in switch to turn it on and off and the reset button worked as well for a majority of my testing. When I hooked the case switch back up to the ATX header I had the same problems.

 

I did notice from time to time after resetting the P/S switch and draining the MB, that when I turned it back on it would give 3 small beeps. Not certain what that means as it didn't sound like a normal post test error.

 

I have tried plugging the FD power connector on the board as someone suggested but it did not help. (Only one GPU so I didn't think that would matter) I also flashed the bios to 12/7/05 and that didn't fix it.

 

I have also played with every bios setting related ACPI, ATX switch, wake on power & mouse, and even played with the 5VSB jumpers on the board for both USB and PS/2. (Back to default 5V now)

 

Any clues? Please Help!

[BigKohones]

I switched mainboards only cause my DFI Expert died, the new Asus A8N32 Deluxe does not exhibit any issues with cold boot as described here and as I experienced with the Expert. I'm RMA'n the DFI board. The question now is what do I do with it when I get it back; I figure it will take atleast 3 - 4 weeks for a full turn around and by then X16 boards will be mainstream dropping the already falling price of the expert more.