Comp turns off when desk or case gets bumped

Luther

Distinguished
Mar 1, 2009
2
0
18,510
I just built this machine, poured much time and money into it, and it was working like a dream for a week, (with some software XP 64 bit issues I resolved).
Now when-ever the slightest impact comes near the thing it turns off. I considered it a PSU/Mobo problem I opened the case and checked all the connections, I can't see anything wrong or loose. It is crowded in there though, + the PSU is a pretty good one with enough power to handle everything in there.
Here's my specs, any help would be greatly appreciated as this is stressing me out a little, and I can't afford to builld another.
Here's my H.W.

Motherboard: P5Q DELUXE

Basic Input Output Systme(BIOS): Default System BIOS

Central Processing Unit(CPU) X 2 -> (Intel Core 2 Duo E8500 Socket LGA775, 3.16 GHz)

Intel(R) Pentium(R) III Xeon processor

Intel(R) Pentium(R) III Xeon processor

Physical Memory X 4

1024MB

1024MB

1024MB

1024MB
Ram is OCZ 800

Hard Disk: ST3500410AS (466GB)

Video Card: ATI Radeon HD 4800 Series

Monitor: SyncMaster 2253BW/2253LW,SyncMaster Magic CX2253BW/CX2253LW(Digital)

Audio Device X 2

ATI Function Driver for High Definition Audio - ATI AA01

Creative X-Fi Audio Processor (WDM)

Network Adapter

Local Area Connection - Marvell Yukon 88E8001/8003/8010 PCI Gigabit Ethernet Controller (Connected)

1394 Connection - 1394 Net Adapter (Connected)

Local Area Connection 2 - Marvell Yukon 88E8056 PCI-E Gigabit Ethernet Controller (Disconnected)

Keyboard: Standard 101/102-Key or Microsoft Natural PS/2 Keyboard

Mouse: HID-compliant mouse

Power Suplly: 750 QUAD Silencer

OS: Win XP Pro 64 bit

Case Antec 300 Gaming Case

......Thanks for reviewing all who offer help.
 

Luther

Distinguished
Mar 1, 2009
2
0
18,510


For got to mention I have 4 fans running in the case