When you turn on the computer it makes a series of stringed beeps for a second also when turning it off, keyboard and mouse does not work

This code in beeps is depending on which brand BIOS is running your motherboard.
Have a look here to get some aid on that:
https://www.lifewire.com/how-to-troubleshoot-beep-codes-2624889

Good luck finding out.
A.Misset

Not so sure about this but I hope this will help.
-try to disconnect all the cables from the back (monitor, keyboard, mouse, usb's, power cable, etc.)
-then disconnect all the card (video card, sound card, NIC) if all are integrated then you dont have to.
-connect just the power cable
-try to turn on the computer and check if it beeps
-if it does not beeps need to replace the motherboard but before you do this check if the fan will spin even for a single second if does not spin then you also need to replace the power supply as well
-if it beeps then turn it off again.
-connect the video card and connect the cable of the monitor, keyboard and mouse
-turn on the computer then check if theres any display
-if theres no display check for any beep indication. and right it down on a piece of paper on how many times it beeps and if its long beep or short beep.
kindly provide an email if this things does not work so that I can give you a resolution.

If all the keys on the keyboard have stopped functioning follow the instructions below to reconnect the keyboard.

This problem is likely to be a lost connection. The connection between the mouse and the USB mini-receiver or the keyboard and the USB mini-receiver can be lost due to several reasons such as:

• Low batteries
• Moving the USB mini-receiver from one USB port to another
• Moving the USB mini-receiver to another computer
• Plugging the USB mini-receiver into a USB hub or other unsupported device such as a KVM switch (your USB mini-receiver must be plugged directly into your computer)
• Using your cordless mouse/keyboard on metal surfaces
• Radio frequency (RF) interference of more powerful wireless devices such as:
  • Wireless speakers
  • Computer power supplies
  • Monitors
  • Cellular telephones
  • Garage door openers

Eliminate any problem sources mentioned above that might be affecting your devices.

Follow the procedures below to reconnect your mouse and keyboard.

1. Make sure the USB mini-receiver is directly and securely plugged into a working USB port on your computer.
   
2. Make sure the mouse is turned on. The on/off indicator on the bottom of the mouse should be green. If the on/off indicator is not illuminated, press and hold the red connect button on the bottom of the mouse until the on/off indicator is green.
   On / Off Indicator
   
   
3. Press and release the red connect button on the underside of the USB mini-receiver. This will broadcast a signal to your mouse. This broadcast will last only a few seconds, so you must perform the next step quickly.
   
   Red Connect Button
   
4. Quickly press the red connect button on the bottom of the mouse for 1 second, then release it. The power indicator will flash briefly and then turn green. The mouse is now connected to the receiver.
   
   Red Connect Button NOTE: Holding down the red button on the mouse for more than 2 seconds may cause your mouse to turn off instead of connecting. If this occurs, start again at step number 2.
   
5. Move your mouse to see if the cursor moves. If the cursor follows the mouse movements, your mouse is now connected.
   
6. Press and release the red connect button on the underside of the USB mini-receiver. This will broadcast a signal to your keyboard. This broadcast will last only a few seconds, so you must perform the next step quickly.
   
   Red Connect Button
   
7. Quickly press and release the red connect button on the underside of the keyboard.
   Keyboard Connect Button
   
8. You will hear a short beep. The keyboard is now connected to the receiver.
   
9. Test your keyboard to see if it is working. If the mouse now works but the keyboard still does not, see Knowledge Base article 9144.
   

If the keyboard is USB, and I am assuming it is, try plugging it into a different USB port and allow a minute for the drivers to install automatically.

If the keyboard is PS2 (round purple connector), make sure you have it plugged in BEFORE you turn the computer on, or it won't work.

If neither of these work, try a different keyboard; if that works, the keyboard needs to go.

Good luck!

Usually it beep if the keyboard stuck or the mouse or mem...check with your cmos by clicking F1 or del after booting and check and see the mem and make sure that your mouse and the keyboard are connected and working...hope that help

all the keys just make a string of random letters... it's a sony vaio

The mouse or keyboard does not work at all
If your wireless mouse or keyboard is not working properly, check the following:

1. The mouse is designed to enter a suspend mode after 20 minutes of inactivity. Try to reactivate the mouse by clicking the left mouse button.
2. If the underside of the mouse has an on/off switch, make sure to set the switch to the "On" position.
3. Restarting the computer may resolve the problem, at least temporarily, so that other troubleshooting steps can be applied.
4. Make sure that the keyboard and the mouse are within 100 centimeters (39 inches) of the receiver. If the receiver is attached to a cord, position it so that it is on the same level surface.
5. Verify that the batteries are correctly installed in the keyboard and mouse. If possible, use a fresh set of alkaline batteries.
6. If the receiver is a USB receiver, unplug it, wait for five seconds, and then plug it back in. Wait about five more seconds and then test the mouse and keyboard again.
7. Reset the keyboard and mouse connections :

Note: The following connection sequence must be completed within 60 seconds.
With the receiver plugged in, press and hold the Connect button on the receiver until the activity LED flashes.
Note: Some HP computers have receivers built into the front of the computer; such as TouchSmart 700 Series PCs and Digital Entertainment Centers. Look for a small Connect button built into the case. If you have a TouchSmart 500 or 800 Series PC, the receiver plugs into a USB port on the underside of the case and does not have a Connect button - skip this step.

There must be interference on the signal from the mouse by the second PC

Make sure that there are no power cables close to the mouse or receiver, I have seen this cause problems many times.

You could also try changing the channel in the router settings in case this is causing the problem, it may be on the same channel as the mouse but only interferring when the second PC is turned on, ta, HPC

Solution for the mouse. I have 8 KVM's. Most of my computers work with the KVMs. On 1 inland KVM the logitect and Microsoft optical mice do not work on one computer (but work with the other computers). They both are USB. I hook them up with a USB to PS2 adapter. If I use a ps2 ball mouse connected to the KVM the mouse works. All the Mice work if I directly connect them. Since I do not want a ball mouse I got a Frisby optical PS2 mouse. It works with all the computers on the KVM's.

I do not have a solution for the Keyboard yet. 1 computer (ASUS MB) on my trendnet or belkin 4 postion KVM does not recognize the keyboard.

Press and HOLD the Power button for 5 seconds ...this will turn off computer ......her's a list of beep codes http://www.computerhope.com/beep.htm

These may help !

Try a different keyboard /mouse if you can /make sure NO pins are bent or missing on PS2 connection .....

When booting up computer hold the DEL key down this will take you into the BIOS.......Select LOAD DEFAULTS usually F10 ...you'll see it on bottom of screen .....Save when prompted and see if it boots......Good luck