Dang! No Power!

[OneSpirit]

Wellsir ... I'm having a bad energy day ... seems like so much is going wrong ... this is my i core 7 machine. Went to boot up ... nothing. Replace the power supply with a new one ... nothing. Motherboard problem? The motherboard, video card, power supply all less than a year old.

[bdub]

reset the cmos on mobo using either with the jumper or taking the battery out for ten minutes.

[Karlsweldt]

Back to a working state or still a problem?
Still a common issue, if the BIOS battery dies and mains power is taken from the PSU, then the real-time clock is not functional, and possibly no life signs from the motherboard.
While mostly not an issue today, still worth a look at capacitors to see if any show signs of failure.

[OneSpirit]

Wellsir ... I pulled the battery to reset the CMOS ... that got the power back ... the computer will boot, but it will not go into windows. As soon as the windows logo comes up the computer crashes (quick blue screen) and reboots. Same thing when I try to go into safe mode. Now that I think about it ... the time on the computer would be wrong at times. Could there still be some kind of hardware problem?

[Karlsweldt]

Time and date of the real-time clock are important to the OS and other programs. If off by several months date, or many hours time, the OS may sense a security issue and refuse to come through. Ensure your time zone is set properly also.
Average life of a BIOS battery is about 3 years, depending on use. It is only a redundant backup for when no AC mains power is feeding the PSU, in 'off' state. The PSU provides the +5 volt stand-by power for the BIOS, CMOS, USB and other features.

[Mr T]

Bad hard drive or overheating CPU? Try reseating all cards and cables (inc RAM). Remove the heatsink from the CPU, clean and replace the thermal paste and of course clean the fan and the heatsink. Windows(10) had a major update that has caused issues, but stopping the system booting, no chance.

[OneSpirit]

I reseated everything ... once again ... no power. I don't understand it. When it was booting I did a test on the hard drives and memory ... they passed. The cpu fan was loose and I made sure it was secure. Last time I reset the CMOS I left the battery out for a day. I'll let it sit for today with the battery out and try again tomorrow. I checked the battery with a multimeter and I'm getting over 3.1 V.

[Karlsweldt]

The PSU will provide a 'static' current source to the system until it stabilizes, then present a 'power good' signal to motherboard timing circuits for operation. That "PG" lead is a gray one at the back of the main ATX power plug. Should be right around +5 volts, if all is good. Only a .3 volt lower, and timing circuits may not respond.
Ensure the PSU has sufficient reserve for all needs. And is a quality unit, not some cheap over rated bargain.
A PSU is not immune from the "bad caps" syndrome. May be worth opening the box and having a look.
First, pull the AC mains lead, try a few starts to drain reserves. Then it should be safe to look around inside the PSU.
But be very wary around the large capacitors on the input side.. they can harbor 200 volts or more!
Any capacitors with domed tops or leakage signs are bad. Not worth trying to replace them.

[bdub]

what happens when you go into the bios screens and look around? check the temps on the cpu while there, and any other temps and voltage reading to make sure they are fine. if the bios is not freezing, then do a memtest run (pre-os program to check memory). if that comes up clean, maybe you can repair the os or try installing a new one.

[OneSpirit]

Wellsir ... I swapped out the brand new out of the box Rosewell PSU and put the PSU I started with and the computer booted. I only used that Rosewell a couple of times ... how could it go bad that quick? I will use the install disk and see if it can repair windows.