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What would happen if I remove the bios chip and power on...

Posted: Mon Dec 03, 2007 3:06 am
by bioscrasher
1. Would it destroy my mobo instantly?
2. Would it start any devices such as the fan or HDD?
3. Anything...?

I have been wondering about this for some time now but I could not get my hands on something concrete. I think what I need is 1) diagram on how things start when a computer is powered on and the order of how they are started and 2) the same as (1) but this time assume that the bios chip is removed. A simple question but for someone like me, this is already rocket science.

Any information on this is very much appreciated. Thank you in advance...

Posted: Mon Dec 03, 2007 11:38 am
by cp
1. no. no harm to anything.
2. as long as power is supplied all devices connected to power would run/spin-up.
3. the mainboard will not boot, obviously.

the first thing happening after power up is (after waiting for stable voltages which is a hardware feature of the power supply): executing code from the bios. if the bios is not there nothing will happen.

Posted: Mon Dec 03, 2007 4:05 pm
by bioscrasher
thank you for the reply...

just to make sure I get perfectly what you are saying... without bios, devices would not start/run/spin even if power is supplied... does this include the fan (CPU) or is the CPU fan NOT controlled by bios? And just as a follow up question, is this the same for desktops and laptops?

i really appreciate the information... thanks again...

Posted: Mon Dec 03, 2007 9:00 pm
by cp
2. as long as power is supplied all devices connected to power would run/spin-up.
quoting myself...

all devices would start/spin-up when power is supplied. but they are just sitting there being dumb.

connect a harddisk to a power supply and turn it on. the drive will spin-up immediately even if there is no ide controller connected to it. connect a fan to a power supply and it will start spinning...i don't quite get what you're up to.

Posted: Mon Dec 03, 2007 9:22 pm
by bioscrasher
i am sorry if ever i made it quite confusing... i may not have written my question well.

To a laptop, if powered ON... everything starts... the fan, LEDs will light up and it will start to POST/boot from a bootable media. If bios chip is removed these would not happen or it would not go into POST. But would the processor fan spin at the very least? Or is the fan also being controlled by the bios that without the bios chip the processor fan would just sit there doing nothing (not spinning)?

Again thank you for the help and most of all thank you for being so patient with me.

What would happen if I remove the bios chip and power on...

Posted: Thu May 22, 2008 12:17 am
by fzabkar
I believe some old jumperless socket 7 motherboards would power up the CPU with an initially high voltage (because some socket 7 CPUs required as much as 4V) until they determined which CPU was present, and then the Vcore was reduced to the required level as specified by the BIOS. If the BIOS were absent, then the Vcore would remain high, possibly destroying the CPU.

That's just speculation, though.