Sleep mode(Vista) = system powers off

Problem: Computer immediately powers off when put into sleep mode.

Background: 2 weeks ago there was a power surge. Get home from work, computer is off and it won't turn back on.

Solution: I ordered new power supply(did not come with new power cord so I'm using the old one), connected it, and computer powered back up and everything was working great (or so I thought).

Then I tried to put it into sleep mode and it powers off. It doesn't run through a shut down process. It just powers off like I pulled the plug.

1. I did have to remove the CPU heat sink allowing me to replace the power supply. I reattached the heat sink but did not put new thermal compound on it. But before you yell at me, the cpu is operating at about 78 degrees with an internal system temp of 98 degrees. I don't think the compound is the issue.
2. I checked the power setting is BIOs. Everything is enabled that should be.
3. I looked at the power options in the control panel; again it's all good there too.
4. I don't notice anything "fried" on the mobo.

I really don't think this is a configuration problem but I'm open to any suggestions.

 

The trouble with a power urge, is that it can damage parts on the motherboard, and is not always obvious- no surge protector, then ?
I would check all the leads to the motherboard, by remove and replace, in case there is a loose connection,that might have occurred whilst replacing power supply.
I would also reseat the cpu with artic silver, or,whatever else you might use,as the cpu temperature is a bit high, nd the internal temperature, look a bit high- you have not stated the cpu type (p4, core2duo, amd) Different cpu's will run hotter, or, colder- my old 3ghz p4 would run that hot, and they were a bit notorious for running hot, but my old core 2 duo,ould run at 35 degrees.
Also , if you look in majorgeeks downloads, you should be able to find a software tool to check out your motherboard.

 

great recommendations, thanks! I'll try a few more things and report back if they resolve the issue.

I was plugged into a Belkin surge protector. I was probably as protected by an ordinary power strip as I was with this thing.

CPU is a Core 2 Quad 2.66Ghz (not overclocked).

 

It could also be that the power supply is defective. Do you have another computer you could borrow a PSU from to try it out?

 

I thought the temperatures were a bit high- Here is Intel's recommendation (38---39deg)
Looking around it seems that those running this cpu are running between 35, and 50 deg.

http://www.ask.com/bar?q=core+2+quod+2.66+running+temperatures&page=1&qsrc=2417&dm=all&ab=5&u=http%3A%2F%2Fwww.intel.com%2Fcd%2Fchannel%2Freseller%2Fasmo-na%2Feng%2F299986.htm&sg=q4PyO9tbHTr5Q9OG1bFV5SyZARNchkXhCHZN4EB8BVo%3D&tsp=1278707543590

I found that cpu monitor works with my core i7 2.66 and I am running around 50 deg+, on all 4 core's- but it is a Dell, and I have not got around to playing with it much , yet, as I have been setting up partitions, and copies of the various systems, and in between playing with silly programs, but , its not a problem, as yet.