Found this on another site and thought it might come in usefull for some people.
A guide to Preventing and Recovering from Bios corruption, and work arounds for Cold/Warm Boot Issues
Symptoms of bios corruption/"4 led’s of death"…
Well the main, and most obvious symptom of bios corruption, is the same as any other motherboard, and that is a failure to POST under any circumstances, when all other hardware is tested, and Cmos had been cleared(Read Here for the official DFI way of clearing cmos, by "Angry Games")…..
But w/ the Lan Party ultra B, there is another symptom, and that is what is commonly called the “4 led’s of death”. This is caused by bios corruption. It is when the 4 diagnostic led’s on the mobo,(which are supposed to cycle during post, and then light up solid after post), all 4 light up as soon as the power button is pressed, and after that is doesn’t post, it will only set there, will that the led’s lit….
Please also note, that if you have resently installed a HSF that bolts up using the monting holes around the cpu socket, and afterware, you are unable to post, and have "4 leds of death", it is likely this is because there are small SMD componates around the mounting holes, and are commonly crushed/damaged durring istallation on bolton heatsinks. You should first carefully inspect your board for damage, befor you assume a corrupt bios to be the cause.....
Ways of recovering from bios corruption/4 leds of death…
Well if you have a DFI NFII mother board and you have diagnosed it as having corrupted bios/4 leds of death, you have a few opions.
First thing first, always, always, always, try clearing Cmos first. Power the mobo down(do not turn off the PSU first, but hold the power button down until it shuts off. THEN turn off the PSU. Wait till the PSU if fully discharged (you will see the power LED’s go off) Then clear cmos using Angry Games way then try to repost. Many have had success w/ trying this repeated times, and maybe they didn’t get a post after one clear, but maybe after 5 clears, it posted….
The second thing I will suggest sounds off the wall but many have recovered though this method. First find the two swiches on your motherboard, reset and power. Push them both at the same time, but release only the power button, and continue to hold the reset button for 10-15 secs, and then release it. After releasing the reset button, some have had a mobo that refused to post w/ infinite cmos clears, to post.
Thirdly I would try a clear cmos in conjunction w/ setting the 100fsb jumper to 100fsb, and trying to post. This has worked for some.
As probably your last option I would try using different ram or cpu if available as a last resort. For example, after i experienced “4 leds of death” after putting in OCZ 4400(3-4-4-8) with out clearing cmos(I had BH-6 in w/ timings of 2-2-2, which the ocz will not run at), the mobo refused to post with my ocz or the BH-6, but I have an odd stick of ram, it doesn’t overclock well, but it will post at 2-2-2 or 3-4-4, or anything in between, and after inserting this ram, the mobo posted no problem. This may have been a fluke, and may not work for others but this was my personal experience and worked many times...
And finally possibly the most common solution to the problem is either Hot Flashing the Bios, or RMAing the board as a last resort. (Hot Flash Procedure described below…)
Way of avoiding Bios Corruption/ “4 led’s of death”
The first and one of the most important things is to never set the ratio/divisor on the memory, to anything besides 1:1. NEVER. Almost Guaranteed corrupt bios. Always leave 1:1. Also Never try strange ram timings like 1.5Cas, or 1 Precharge, ras to cas, or ras to ras. The lowest that your Cas, Ras to Cas, Ras to Ras, or Prechage should ever be set to is 2, unless sometime in the future there is ram released that supports such timings….
When overclocking don’t experiment w/ frequency adjustment in bios initially. Set all your Voltages, and your timings in bios. Then use Clockgen to adjust FSB, and increase clock slowly & do all of your tweaking from windows, until you have tested your desired setting to be fully stable, then set them in bios.
When setting up bios after a Cmos Clear/bios flash. Or anytime that the voltages/frequencies are low(i.e. 10x200@1.575vcore) and say you know that your system is stable at 10x250@1.8vcore, change your VOLTAGES first, save and exit, and then change your frequencies. That way you cpu/system already has the voltages it needs to run the clock that you are about to set it to. Also if you plan on loading from Cmos reloader, set your voltages, save and exit, and then come back in to bios before you load you saved cmos setting from the reloader, just as the above case, that way you are sure you system get the voltages it needs to run the higher clocks, BEFORE the higher clock is accually applied & set the frequencies one at a time(set one save cmos & set one save cmos...)
When changing hardware(ie ram) always, always, always clear Cmos before trying to post. And sometime even if cmos was cleared you will still get a no post/ 4 led’s followed by a single tone beeeeeeeeep……..beeeeeeeeep…….beeeeeeeep….. From there don’t get exited, the LAST thing you want to do is flip the switch off on you PSU, or unplug you comp, (on DFI it is not good to cut off the comp using PSU switch , or unplugging, this could result in bios corruption. This is how I corrupted my bios the second time. After i got my NF7, and could easily hot flash, i tested this by changing ram out, and then trying to post, i got the Beep....Beep....Beep.... and every time, from there, if I turned my PSU off, or unplugged, my bios corrupted, and i had to hot flash. But if i just hit reset(sometimes this would make it post), or held the power button until shut down, cleared Cmos, and then try to post again, it was fine, no corruption). From here first try hitting the reset button, usually this will bring it out of it, and allow you to post. If it doenst allow you to post, then hold the power button down until it shuts off and try clearing cmos again.
Be careful when flashing Bioses, always set you current bios to stock settings, before flashing, then once you have flashed, as stated above, don’t set everything at once, but set you voltages FIRST, then save and exit, post, inter bios again, set frequencies. Also there have been afew people that have had problems going from older bioses to the newest ones. If you flashing from an older bios, try taking it in steps, and going to a stightly newer bios, and then another, and then on to the one you are trying to flash to.
The last and possibly the best way to avoid bios corruption, it to always use a bios saviour, or to keep an extra preflashed bios chip on hand. This is not avoiding the 4 LEDS OF DEATH, but if all else fells its the easiest & fastest way back to a working mobo.
Here is the bios savior for DFI mobo's
Hot Flashing how to’s
The hot flash is usually what will end up being the final resolution to most corrupted bioses.
What is hot Flahing
Hot flashing is a process that involves using another machine to flash your corrupted bios. The host mobo of choice is usually the NF7/NF7-s,(although it is probable that many NFII motherboards should do fine ,though it is the NF7 thats been tried and tested).
The way I prefer to do it, is prior to booting the NF7, I *gently remove the bios chip w/ a small flatblade screwdriver/ or toothpic like object, and run a loop of string under the bios chip(dental floss) so I can just pull the string to remove the chip. After the machine is booted, instead of having to use the Screwdiver on a live mobo just pull the string. OK then I boot the NF7.
After I get to a desktop, I remove the NF7 Bios chip. Then insert the corrupt DFI bios chip. Open WinFlash, and flash the bios to a bios that your sure works(such as the 1-21/31 beta’s) . After the flash is complete, shut the NF7 down, and remove the bios chip. Then put it back in the DFI, Clear Cmos, and then Cross you fingure. DO NOT LET THE NF7 OR HOST MOBO BOOT WITH THE DFI CHIP, as soon as it shuts down if for some reason it wants to reboot pull the plug on the PSU at this time and stop it from booting.
Some prefer to hotflash using a Floppy disk and “awdflash”, but due to the slight complication of using some of the “switches” to be able to flash, I prefer using winflash from a windows desktop. To me it is much simpler, and i have had great success.
Usually most Hot Flashes are successful.
Last Resort
If you have tried all of the above, and have had no success, hot flashed with no success, and have tested all componets to be good, (including Cpu, ram, PSU, Video Car, etc, and only the mobo remain). Then it is probable that you mobo is dead and as a last resort, you may have to RMA. I myself have never had to go that far, If you take your time & think about what you are doing you should have success to.
I hope this tread will be of some help to all.
