Loud CPU Fan, No Monitor Display HELP!

[neil.2298]

sometimes, my computer does normally turn on
but sometimes, it does not. the cpu fan gets loud like its gonna RACE! and there is no video display on the monitor
what i do is that i reinsert the dvi cable on the back, and it works and sometimes it doesn't and i really insert it so hard... still wont, but sometimes it does
so i would want to find out what causes this sort of problem, here are my specs

here is a long description of my current computer

Code: [Select]

Computer:      Hewlett-Packard PPPPPPP-CCC#MMMMMMMM
CPU:           Intel Pentium Dual Core E2200 (Conroe-1M, M0)
               2200 MHz (11.00x200.0) @ 2194 MHz (11.00x199.5)
Motherboard:   MSI Boston
Chipset:       Intel G31 (Bearlake) + ICH7
Memory:        2048 MBytes @ 332 MHz, 5.0-5-5-15
               - 1024 MB PC5300 DDR2-SDRAM - Kingston 99U5316-010.A00LF
               - 1024 MB PC6400 DDR2-SDRAM - Hynix (Hyundai) HYMP112U64CP8-S6 
Graphics:      MSI R5450 (MS-V234)
               ATI Radeon HD 5450/5470/5490/5530/6230/6250/6290 (CEDAR PRO), 1024 MB DDR3 SDRAM
Drive:         SAMSUNG HD251HJ, 244.2 GB, Serial ATA 3Gb/s
Drive:         TSSTcorp CDDVDW TS-H653Q, DVD+R DL
Sound:         Intel 82801GB ICH7 - High Definition Audio [A1]
Sound:         ATI/AMD Cedar/Park/Robson - High Definition Audio Controller
Network:       RealTek Semiconductor RTL8101E Fast Ethernet NIC
OS:            Microsoft Windows 7 Ultimate Build 7601

full pc spec [detailed]
http://www.mediafire.com/?1rr176oee8t3p3j
virusscan:
http://www.virustotal.com/file-scan/report.html?id=32a5c8858fc26c15bd0584f8e56d76779f6b034e3764f370eaa2709f6af065be-1325170857
^the LOG IS TOTALY HARMLESS

[Daisymae70]

There isn't always just one cut and dried answer.  It takes some troubleshooting.

"The best thing would be to strip the system and determine the faulty component(s)

Inspect the MB for any damaged capacitors or burn marks.

Test the RAM individually.

Test with another graphics card or test the graphics card in another system.

Test with another PSU."

[reddevilggg]

Has it ever worked normally? If yes, i'd take out the graphics card and try the conventional way of connecting the monitor with the VGA.