Computer won't boot

[Soundlessleaf80]

Alright, this is my last resort before taking it to a mechanic.

Basically this morning I went to turn on my pc, the fans usually only run at full speed for roughly 5 seconds before slowing down to idle while starting up, but this morning they were full speed all the time, I got no signal from the Gfx card, over the day I've tried swapping the psu, replacing ram, replacing cmos battery the farthest I got was when I unplugged and replugged a power button connector and removed my gfx and wireless card to use the internal gfx, whenever I stick anything in any expansion slot, the pc refuses to boot up, I get full speed fans, black (both gfx card and internal) screen.

I've pretty much exhausted all my options here, any suggestions?

Specs: Lenovo think centre a58e
Ram: 3 gb
Gfx: Asus GeForce 8500GT
CPU: Intel pentium dual core

 

[Pentium4User]

Hello is this the tower model or the sff one and is it dusty or clean because all I can think is if dust in in the pci/pci-e slots and I assume you tried 1 card at a time just in case 1 bad unlikely they are bad but it happens. If non of these help you can take it to IT place/ computer repair store If they say it not fix able and need to buy a brand new pc or it over 200 don't listen you can buy the exact same mother board for 50 or 40 dollars on ebay if it needs to be replaced.