|Sounds like you didn't even troubleshoot. All you did was run out & buy a bunch of parts that may or may not have needed replacing...not only that, but you put them all in at once!! You should have done exactly the opposite.|
- double check that the new PSU is connected properly - main ATX plug & 4-pin ATX12V plug are securely attached to the board.
- take out the new video card, the wireless card & all the RAM except one original stick.
- reinstall the original video card
- unplug the cables (both data & power) to all the drives (optical, HDD, floppy)
- unplug ALL external devices except for the keyboard. Use a PS/2 keyboard, not USB, & make sure it's plugged into the correct port.
Now try to bootup. Do you hear a single POST beep? If not, either your board or CPU are bad. To double check, take out all RAM & try to boot up...if the system doesn't beep like crazy, you've pretty much confirmed that it's either the board or CPU that are bad. Now you have to somehow determine which one.
BTW, you refer to the PSU as an Aspire ATX-AS520W? Aspire changed their name to APEVIA a long time ago. They claimed the name change was to cut down on confusion with Acer Aspire products, but IMO, the real reason was because they were getting negative feedback due to the faulty 500W PSUs they were pumping out at the time. There was a class action lawsuit brought against them.