MoBo possibly fried, some advice needed
 

Ok, here's the skinny. I'm working on a Gateway E4300 with the following specs:

Intel (Luxemburg) 915G Motherboard
Intel® 915G Chipset
2x 256 MB DDR2 Dual Channel 400 MHz SDRAM Module
Intel Pentium 4 540 J (3.20 GHz) CPU
180-Watt Power Supply
Western Digital 160-GB 7200-RPM 80GPP 7M SATA Hard Drive
Lite-On 48x 32x 48x 16x CDRW/DVD Combo Drive

The problem is that upon powering up it will not go through the POST. In fact, the video, LAN, KB/Mouse, etc doesn't activate. I've used a multimeter to check the voltages and there is no short in the PS nor the MoBo. The CPU is getting power, as is it's fan. Nothing is output to the screen, the monitor goes into power suspend mode due to not getting a signal. There are no beeps.

My best guess from a visual inspection of the MoBo, finding no scoring or burning, and checking volatages, finding no shorts or lower than expected power reading is that the CPU itself is the problem, and I think it's the second step in the POST where the CPU is supposed to exit the reset status mode to execute anything, and it's not. Any ideas? Thanks!

Best guess would be that your power supply has gotten a little old(they lose output power as they age). It may not be able to put out enough amps to run everything. A 350watt PSU is considered pretty small these days with a 500 watt being about average (1000watt psus are available). Unplug the HD and the DVD drive and try again.

Sounds like the PSU to me too. Personally I would not recommend using 180W power supply as it's just plain underpowered, and would recommend at least a 300W or 350W. That said, have you recently made any changes to your system (adding RAM, connecting new drives, etc) Don't overlook the obvious, it may just be somethings disconnected

Tried running it with just the MoBo, CPU and RAM installed, and still nothing. No beeps, no output to screen. No changes recently. Also tested with a known good 250W PSU, same result.