Computer won't post if i enter bios

jim5000 · 27 Dec 2006 at 10:21

At the moment, my bios settings are all incorrect, they are at the settings that you get if you clear the bios completly with the jumper. My memory timings are wrong, the cpu is set to the wrong speed, the boot devices are all wrong etc. etc.

The problem is, if I enter the bios to change anything, even if it is only whether to display the boot logo or post screen, the computer refuses to boot until i clear the cmos again. Sometimes the computer won't turn on at all until i clear the cmos, and sometimes doing a soft reboot from windows sends it to sleep until, you guessed it, i clear the cmos again.

Does anyone have any idea why this is happening and how i can fix it it? Specs are

Abit AN-8
A64 3000 venice
2gig OC value ram
500w psu (without a 24-pin connector)

Minstadave · 27 Dec 2006 at 10:45

Sounds like your system is unstable unless it is in the failsafe configuration you get when you clear the CMOS.

First guess would be dodgy RAM, try removing one module see if it posts then if it doesn't try the other.

I'd reseat the CPU if temps are looking high on the BIOS hardware monitor (obviusly you'll have to reset the CMOS to get into the bios to check this

).

flying grouse · 27 Dec 2006 at 10:55

jim5000 said:
At the moment, my bios settings are all incorrect, they are at the settings that you get if you clear the bios completly with the jumper. My memory timings are wrong, the cpu is set to the wrong speed, the boot devices are all wrong etc. etc.

The problem is, if I enter the bios to change anything, even if it is only whether to display the boot logo or post screen, the computer refuses to boot until i clear the cmos again. Sometimes the computer won't turn on at all until i clear the cmos, and sometimes doing a soft reboot from windows sends it to sleep until, you guessed it, i clear the cmos again.

Does anyone have any idea why this is happening and how i can fix it it? Specs are

Abit AN-8
A64 3000 venice
2gig OC value ram
500w psu (without a 24-pin connector)

check your HDD before going any further, try a swap with a known working HDD

Minstadave · 27 Dec 2006 at 10:58

flying grouse said:
check your HDD before going any further, try a swap with a known working HDD

A dodgy HDD wouldn't usually stop a system POSTing, it can cause it to hang during the drive detection process, but I've seen daft things stop a computer working before so give it a try

t31os · 27 Dec 2006 at 14:59

I have a PC doing the pretty much the same thing here, havnt tested RAM as the culprit yet, so thats given me something to work with.

PC boots up fine, windows the lot, if i touch any bios setting it boots into windows etc, but i get no display on screen, if i clear cmos, boots fine again.

Not vid card, not hdd, but never thought to try memory.... will give that a shot now.

System in question is proberly different to yours, this one is a 2700 Sempron on an NF7-S, (running at bios defaults) <--- i'm sure you can see my pain now..

jim5000 · 28 Dec 2006 at 20:31

Right, I've changed the memory and tried booting with a minimal setup (cpu, gfx card, memory) and am still having the same problem, the bios HAS to be reset befor the computer will turn on at all. If i reboot, i have to clear the bios before it will boot.

The cpu temps seem to be fine (29oC in windows), and I have tried changing the memory but it doesn't seem to make a difference.

Can anyone tell me what the default settings (fsb\multi) for and a64 3000 are, and also, what should I be putting in the memory section for default speeds (I think its pc2700 ddr memory) as i think this may be causing a problem. When i reset the bios and it actually boots, I get a speed error, press f1 to continue...

This is what it is currently running at (1 stick of 512mb memory rather than the normal 2 1gig sticks)

If anyone can help I will love them forever!!

t31os · 28 Dec 2006 at 22:34

1.8 is the default speed, default FSB is 200, with ram set to AUTO it should set the ram to the correct speed.

Not fixed my issue yet, cant change the bios to boot from CD to test....

She gets an upgrade to 939 soon so i'm not too fussed.

Not sure what else to suggest, personally i'll be changing board and memory, so its one of those un-fixed issues for me..... have another few broken PC's to contend with, can't be doing with yet another....

jim5000 · 28 Dec 2006 at 22:41

Huzzah

I downloaded the latest update for the bios, and touch wood, everything seems to be working. I have everything at what I think is default, do these speeds look right? I'm mostly thinking the memory might be abit underclocked? Both memory sticks are the same, I remember I used to have them clocked quite highly. Should I stick the HT back onto DDR400?

t31os · 29 Dec 2006 at 02:52

Yeah thats right, PC2700 is 333fsb, so 164 - 167 give or take.

Timings on the memory look ok to.