Major hardware problem

Ok well first off to start my computer I hit the master power on the power supply and then hit the power on the case and now i hit the master power and it automatically turns on which was my first clue, but nothing ever came up on my screen the standby color never changed. I refit my RAM and CPU and it did nothing same exact thing. I then tried another hard drive I have and have windows installed for my computer on it (I use it just for seeing if any problem i have is software or hardware related) and it did the same thing, nothing. I have a PSU I may try to see if its my PSU but if my PSU went I assume the lights in my case wouldn't come on and im fearing even if it is my PSU that that normally takes the CPU, RAM, and Mobo along with it correct? Any help is greatly appreciated.


Rosewill 500W PSU
AMD Athlon XP 3000+
OCZ RAM (2x512mb)
ASUS Deluxe Mobo
Maxwell 200GB 7200 RPM (Master)
Seagate 250GB 7200 RPM (Slave)
Chaintech nVidia 6600 (AGP 8X)

 

According to the info I will toss a few possibilities but without knowing the entire history of the system and what type of changes you might have done in BIOS some of them might not be applicable:

If this is due to a Hardware related issue then one of the following 3:
~ Faulty/inadequate PSU.
>>> Regardless of its age and capacity this often is the common reason. Generic brand name PSUs should be avoided imo. The overall stability and performance of a computer starts with a reputable, solid and powerful-enough Power supply which is often overlooked especially when people purchaase a generic computer case since they typically come with a below decent quality PSU regardless of their so called high Waltage output.

~ Short somewhere on or under the mobo (loose metal piece of wire or screw).
>>> Grab a flashlight, unplug the power cord from the PSU then dig in the case. If not sure, use a can of compressed air on/under the mobo.

~ Faulty mobo (connectors) or the power switch wires are not connected properly.
>>> Make sure the wires coming from the front of the case are connected properly to the mobo (refer to online manual or mobo'd hard copy manual).

If this is due to a Software related issue then following:
~ BIOS power (ACPI/APC) related settings. For mobos older than a year, I'd also add checking for BIOS update.
>>> If you have mingled with the BIOS settings, resetting the settings to 'fail safe' configuration should help.