Powers on but no boot, subsequent power-ons monitor remains off

[mkuo]

Hi experts,

My build:
PSU: Thermaltake TR2 500W
Mobo: P5NT-Deluxe
CPU: E8400,
Heatsink: Cooler Master Hyper 212 Plus Direct Touch 4 Heatpipe Heatsink 120mm
RAM: 2x1G Transcend (Old); 2x1G Kingston KVR800D2n6k2 PC2-6400 DDR2-800 CL6 DIMM (new addition)
GPU: ASUS 8800GTS
Heatsink: Accelero S1 Rev 2 with Turbo Fans
Case: NZXT Lexa

I was trying to revive an older PC by replacing CPU heatsink and GPU heatsink, adding a new PSU and a few more RAM.

After I put everything together, the PC would turn on, with fans, HDDs, everything sounding like it should, and remains on. However, it will stop at POST. Sometimes even just freezes at the motherboard brand screen and hitting DEL for BIOS or Tab to view POST will not respond. After that whenever I restart the monitor WILL NOT TURN ON.

The weird thing is, if I leave it completely unplugged for a few moments/hours and power on again, I will see the partial/unsuccessful boot end with a freeze. And again, in subsequent reboots the monitor remains off.

I was wondering if anyone has experienced similar issue after putting a PC together?

Tried just booting with one RAM, clearing CMOS, with a PS/2 keyboard, without HDD... still can't seem to pinpoint the issue...

Could this be heat related?

CPU has no bent pins.

One thing I should point out is for the video card, the VRM sink fell off. But I've read cases where those sinks aren't entirely necessary and the card will work without those sinks.

Please advise.


Thanks in advance... and happy holidays!

 

[mkuo]

Help anyone?

Right now I've tested:
PSU, good
RAM, good
RAM socket, good
CPU socket, good (no bent pins)

No one has experienced this scenario? Where after unpowered for a few hours, first boot will show up on monitor and subsequent reboots will not?

 

[mkuo]

I really could use some help here.

This case is a bit different than the typical "no monitor signal" issue on boot.

This is a case where it will show up the first time after several hours totally unplugged and subsequent boots will have no video signals.