Have you tried using just one RAM module at a time? - Generally when RAM goes bad, you more than likely won't even get a display. Still, I would try to operate with one module at a time just to test.
Another common cause for POST failure is that a device is not functioning properly. Start with the hard drive; disconnect it and power on. If POST is successful, you'll see a message stating either no hard drive or no boot file was found. If this happens, you may have a defective hard drive.
If the problem isn't in the hard drive, try disconnecting all devices, and then one by one, reconnect and power on. Come back with results, and system specs.