Pc powers on but dont boot

[tejeshjadhav]

My PC is not booting up since 5-6 months...
 Today morning I tried to start it again and after 4-5 attempts it
started nornally once but again after restarting it stopped booting.

->

The CPU fan turns up, The MoBo standby LED turns on, HDD is spinning
but there is no signal on monitor nor any type of post or beep!

<-

I tried to put ram sticks one by one in different slots.
I tried to take out all components and then one by one try to boot but it didnt work.
I even tried to boot PC in bios recovery mode (taking out the jumper) and it post "system at halt" with continous beeps.
I don't think there's problem with PSU as I tested all rail voltageswith multimeter and they seem to be correct!.
The CMOS battery is also new and has 2.95V.

My Ram sticks are clean and working properly
Also HDD is Gr8 as it worked in morning!!
I am not getting what the problem is!

I have :  Intel D101ggc MoBo
              Pentium 4 2.66 GHz processor
              2x Transcend DDR3 1gb RAM
              Seagate 80 GB HDD
              Iball ATX Smps 450Watt

PLEASE HELP ME OUT TO RECTIFY WHAT THE PROBLEM IS AND HOW TO FIX IT!! (pls only technical replies only!) 

[DaveLembke]

Does your motherboard have any swollen or leaking capacitors around the CPU? Given its age it was likely manufactured during the height of the capacitor plague.

Bad Capacitors can cause this if the power supply and hard drive is truly healthy. I am guessing you dont get a BIOS post when it fails to boot which indicates a hardware problem ( Motherboard, PSU, or RAM )... More likely to be PSU, then Motherboard. Also to mention it could still be power supply issue as for if the power supply is weak at the initial boot but then comes into voltage spec you would see the voltage as within the correct operating range, but because it booted with weak (undervoltage) at the initial initialization sequence of the motherboard it will hang at a black screen. There is a timed window of opportunity for everything to boot within a timed sequence. If that sequence is tripped up by a second or so undervoltage state it wont boot successfully. If your capacitors are healthy looking I would still swap out the power supply.

http://www.badcaps.net/

[tejeshjadhav]

My MoBo is 10 years old but it dont have any swollen caps!
I have another PSU but i guess it has LOW wattage ie (350Watt and my this PSU is 400Watt)and also i dont know whether its working fine! the only way for me to test PSU is to check voltage....

can u suggest me some way to test the PSU without giving out money (actually i dont have any!)

[patio]

The problem with simply testing voltage is the PSU is not under load...all it proves is continuity...
See if you can borrow a known good one of 400W or better and swap it in there overnite...
You'll know by morning.

[tejeshjadhav]

but the doubt i have is it booted once in morning  and that too without any error! and worked normally

[patio]

Doesn't matter...the PSU still needs to be eliminated as the culprit.

[tejeshjadhav]

i'll try to borrow a PSU and get here back soon!

[xfiles63]

Have you solved your problem yet?Sometimes and most of the time its a bad mother board.Static could have killed or just plain sitting could have killed it.
Since you said it booted once Im going to assume its still working.
I have an Asus board in a machine and if it sits for a long time it wont boot.
What I had to do is reset the cmos by the jumper and remove the battery from the mother board.After resetting everything and installing the battery it boots and runs now.
Im not sure if this is your problem because I have a different mobo than yours.
Mine is a ASUS P5E gaming edition.With an intel core2quad 2.5ghz 1333 fbs.8 gbs of pc 2100 DDR 2 ram.
Good luck.