Blinking power supply, dead motherboard?

[bravebird20]

i have an hp a1220n desktop computer. within the past few months the heatsink fan had been quite loud, especially after running programs that demanded a lot of the cpu. i also recall getting frequent "power surge" messages when connecting an external hard drive that i've used a few times. last week my computer failed to come on and there was only the power supply light blinking. i read a tip about placing a fan near the back of the computer for a minute to start the power supply and the computer and this has been working, however i wanted to completely fix the problem.
i purchased a new power supply and still and yet, the computer does not turn on ..no fan, nothing. this newer power supply doesnt have a green light so nothing at all turns on)
i guess it's not the power supply because i just bought a new one from Corsair....is it the motherboard? if it was the motherboard would my computer even be working after i use the fan to turn it on?
help, help!

 

[Engima]

Which Corsair PSU did you buy? You may have brought one that doesn't put out enough power.

 

[bravebird20]

i bought a "Corsair Builder Series CX V2 430-Watt 80 Plus Certified"
the power that came with my computer was only 250 i believe...definitely less than 430....the new power supply just arrived today and i used it but computer still doesnt turn on. i noticed that when i hit the power button the fan on the power supply moved a tiny bit, like for 1/4 of a second, but then it stopped again and nothing booted.
i used the paper clip trick on the new and old power supplies and both appear to have fans moving when plugged in using the paper clip trick to short the wires...

 

[Engima]

I wonder if maybe something was overheated on the motherboard and damaged itself. Were you able to see what temp your system was going at when the CPU fan was running loud?

 

[bravebird20]

yes, i downloaded speedfan and saw the cpu temps...the lowest it ran was around 54C but wheneve the cpu had to process something it went even higher or if i used firefox while browsing high quality/large file photos, or even use a virus scanner....up to about 80C...but mostly stayed under 65C...at 70C and above the fan would get extremely LOUD! i
if the motherboard is damaged then why can my computer still work after using the fan near the old power supply? if the motherboard was shot, would the computer operate at all?

 

[Engima]

If 54C is your idle temperature then you have a cooling problem in your system. Have you tried cleaning out your computer? Dust does some weird things to computers.

 

[bravebird20]

yes i've cleaned it and i've also applied come more thermal compound, artic silver 5, to the heatsink/cpu...that helped a bit in the beginning but from what i read it takes awhile for that stuff to really benefit the cooling process.
im not sure whats going on and id hate to shove out $50 or so to someone who can diagnose a problem within 5 mins using fancy tools...lol..times are too tough for that.

 

[bravebird20]

well after getting a new PSU and installing a new motherboard (used one though)...this darn system still will not start!!! i have no idea what's wrong but i still have the same symptoms...nothing will start, no fans, no computer screen, no bios...nothing....and the light on the older PSU still continues to blink (the newer PSU has no light)
i'm guessing it might be the CPU but why is it that the CPU will work (and the system will cut on) when i apply a fan to the back of the PSU? i cannot continue to run my system that way, as it overheats....anyone have any sort of advice or ways i can check which components of the system are faulty?

 

[hunter315]

Look at the motherboard, any blown or bulging caps on it? How about dust build up in the CPU heatsink?

Bad caps on a motherboard and lead to a variety of error messages and cause the system not to start.

 

[bravebird20]

well i just bought this new motherboard and it was tested and works, so the company says with a report that was included in the box.
i cleaned the heatsink but maybe i should clean again, even applied thermal compound...but nothing...how clean does a heatsink need to be?! lol

 

[bravebird20]

not sure why but finally got the darn thing to work. lol. im using it now and my temp has dropped to 48C...hoping to get it down a bit less with the breaking in of the new thermal compound i added.
other thing i noticed was a loose screw inside my computer. i removed it but not sure if that's why my computer hadnt been turning on....
darn computers...so complex!

i also reset the CMOS by changing the switch and removing the battery for about a minute. i think this is what possibly got the system to work, but heck, im a newbie so who knows. it was a used motherboard i bought online so i figured i should reset the cmos...guess it paid off

thanks to all of those who've helped me. im really a rookie but really happy things are working better. the internet is WONDERFUL, perhaps the best invention of mankind, ever. when we put our minds together we can really learn a lot. thanks