What's a reset button for?

[JJd]

My computer has a power on/off button of course but it also has a reset button. Why would I use a reset button? Isn't it a bad idea? I thought you where saposed to always wait a short time if indeed you ever had to power down because of freeze-up. Why don't all computers have a reset button? Thanks.

 

[RossGr]

As far as I know all computers do have a reset button. The reset button sets into motion a warm boot sequence. This is better for your hardware then a power off restart. Generally it will accomplish the same thing but not power cycle the electronics. Feel free to use it instead of the power button for a quick hardware restart.

 

[daveshel]

The reset button was pretty universal on AT form factor generations computers, but is not always present in newer ATX systems.

It will interrupt power to the motherboard, effectively rebooting the CPU and the RAM, while maintaining power to the drives and other devices.

In the hierarchy of responses to lockup situations, the use of reset falls in between the less intrusive software reboot (CTRL + ALT + DEL) and a cold boot.

 

[RossGr]

Wether the switch is present on the case or not, ATX mobos have the connection on board for a reset switch. My understanding (which may not be perfect) is that rather then interupting power, the reset switch controls the CPU interupt which starts the initializtion sequence.

 

[ScottMac]

The reset button forces the processor to re-initialize just like a cold boot, but without the power shock/surges associated with a power cycle using the on/off switch.

Most ATX motherboards are never completely "off," even when switched off with the power button. Some power is still fed to the motherboard, slots, processor, and RAM for features like Wake-on-(LAN, MODEM, Key press).

That's why it's important to unplug the system, or use the power switch on the power supply to completely kill power to the motherboard before adding/moving/changing cards on the PCI bus, or adding/moving/changing RAM. Failure to do so may cost you components.

FWIW

Scott