processor?

No, a computer can not run without a processor. What you're describing can be any one of several things.

Tell us what happened just prior to turning on the computer and finding that it won't start.

M$ used to have a Error Code 6 which meant that there was no CPU fitted to the system. Of course when on the rare occasions that this was displayed it didn't mean that there was no CPU Fitted just that something wasn't working right. I've only ever seen this Error Code Once and it was so wrong that it wasn't funny. Of course if M$ had of made it well known what this was I wouldn't have wasted the best part of 2 days trying to find out what it was insisting was wrong and just wiped and reloaded again.

Now to your issue if there is no CPU fitted or working the PS [b]Can Not[/b] run. With the old XT power Supplies that actually switched the Mains Power this was possible but with ATX power Supplies it is not possible.

Here I would be looking at a Faulty power Supply being the first option. What happens is that one of the circuits goes bad and that Voltage stops being delivered. This can be 1.3 Volts, 3 Volts, 5 Volts or 15 Volts.

As the Fans are running the 12 Volt DC Rail has power but there is no guarantee that anything else has any power what so ever. Even though there is sufficient power to run the Fans there may not be sufficient Current to provide enough power to allow a Optical Drive to open or otherwise work.

If the PS is OK look at the M'Board. Look for any budging Capacitors particularly those around the CPU and any other damage. This also includes less obvious things like Dull Solder Joints that have gone bad.

Col

Faulty Fans, Dust and Grime build up on the Heatsink restricting air flow. I would give the inside of the case a blowout with compressed air. When blowing air through the fans make sure that you physically stop them from spinning, as they may generate power and blow something up. Remembering to ground yourself by placing the back of your hand on the Power Supply Unit and not moving your feet. By not taking this precaution it is possible that you could inadvertantly cause damage to the PC from an electrostatic discharge. Then remove the Heatsink, giving it a thorough clean and reseat the CPU applying new CPU grease. If the Fans spin freely when you give them a spin they are probably OK. If there is resistance replace them.

Clean the golden edge of each memory stick with a soft rubber/eraser, remembering not to touch the golden edge of the memory stick. Check with one stick at a time, remembering to disconnect the power from the PC.

Also check Capacitors around the CPU for swelling or bulging.

As the capacitor ages, its capacitance decreases while its equivalent series resistance (ESR) increases. When this happens, the capacitors no longer adequately serve their purpose of filtering the direct current voltages on the motherboard, and system instability results. Some common symptoms are:

* Not turning on all the time; having to hit reset or try turning the computer on again
* Instabilities (hangs, BSODs, kernel panics, etc.), especially when symptoms get progressively more frequent over time
* Vcore or other system voltages fluctuating or going out of range, possibly with an increase in CPU temperature as the core voltage rises
* Memory errors, especially ones that get more frequent with time
* Spontaneous reboots
* In case of onboard video cards, unstable image in some video modes
* Failing to complete the POST, or rebooting before it is completed
* Never starting the POST; fans spin but the system appears dead

Keep us informed as to your progress if you require further assistance. ;) :D