hi

i had some power problems,and after that my moniter gave me a message of no signal and my mouse stoped working also the keyboard

ScottGem

If the monitor is giving no signal, then the PC amy not be powering up. It definitely is not getting a signal from the PC.

How do you know the keyboard and mouse aren't working if you get no signal? what do you mean by power problems.

Abaseeree

first thanks for trying to help. my power supply was weak, so i changed it, after that i started the pc and i found that the is no signal in the monitor and the caps lock or thr numlock in the keyboard doesn't work also.

Thanks
Abaseeree

ScottGem

Again, how can you tell that the keyboard doesn't work if there is no signal on the monitor.

the first issue is to fix the monitor. Make sure that, when you replaced the PS, that you didn't lossen any connections. Make sure the video card is seated properly. make sure the connections to the motherboard are connected tightly.

Steve_C

First thing is to power up the system. Then look and listen for signs. The first thing you should see is a power light on the front of the PC. Unless your using a custom built system and they forgot or hooked up the light wrong then you will need to listen for the fans that run inside. Most power supplies have a fan you can hear that is on the back. If you do not have power and you hear nothing then it is possible that either your using the old cord from the privious powersupply that is molded in a way that makes the metal contacts not reach the newer power supply contacts or something is not plugged in. Possible the power supply is bad too but if its new that is usually unlikely. If your new power supply came with a cord then use that one instead of the old one. I have had similar issues and one bump and my tower would go out.
Now if all is ok with the power light and you hear the fan going then is possible that there is a missing voltage somewhere. Because I cannot see what you have its difficult to determine the problem and hard to tell you where things can go wrong.

Just start from where the power comes in from the wall to the powersupply. (be carefull when you start inspecting cause 120Volts AC can hurt or kill you.) Just insure that all is seated properly. firm pressure will be enough. Check for the switch in the back of the power supply that is is in the on position. I have turned mine off by accident many times. If you hear beeps then that is the motherboard telling you that something isn't right. There are codes for them and each system is different. (Usually depends on the BIOS version)

I hope you figure out why it doesn't work.

BTW. The keyboard and mouse as well as anything you connect to the USB connectors all run off of the 5Volts from the power supply or motherboard. If the power supply isn't at the proper wattage this voltage will drop down to a low level and cause the sysetem not to function. Most of the Fans and CPU run on the 12 volts. Falty fans will cause heat problems which lead to failures later. Always check your systems fans and functionality every few months. Just ensure that the computer can get plenty of air flow too.

Steve C.