mystery keyboard problem

[rezzij]

Several months ago, I began having problems with the keyboard. All 3 LEDs come on, and I can receive no input from the keyboard. I power down - and all 3 LEDs remain on. They will remain on until I unplug the keyboard from the case. Wait a few seconds, plug it back in, power up CPU - sometimes all 3 LEDs would light right up and stick ON when it posted - giving me a keyboard failure message, sometimes it would boot fine. This sometimes would have to be done 5-10 times in order to get computer to successfully POST and boot up. Tried changing the keyboard, worked fine for a day and then repeated same problem.
Finally, in order to maintain usage - family was ordered to never shut computer down - ran it a month with no problems. Finally, keyboard 'died' again ... tried another one, no dice. After a day or two of unplugging keyboard trying to get it to POST, finally I could not even get to a BIOS screen .. talked to several techies, general consensus was that the mobo was bad. Just replaced it with a new gigabyte board, less than 24 hours in - same keyboard problems ... so far unplugging the keyboard, then replugging it in and turning CPU on allows it to boot on first try, but have a feeling it will increase the number of cycles needed ... Don't know if this may be related, but my optical mouse is also lit up all the time - even when CPU is off ? Power supply problems ? I tested the power supply with no load on it, and the voltages seemed fine, but maybe something in the TTL circuit ?

Any clues or suggestions greatly appreciated !

here is the equipment list:
mobo FIC AN19c and GIGABYTE 7VT600-RZ
cpu ATHLON XP-2200+
ram ddr 2700 (2)256meg
ps powertech 300w ATX
keyb LOGITECH internet and DELL quietkey
graphics EVGA MX440 8xAGP 64meg
modem CREATIVE 56kPCI
os winXP-pro

 

[felixc]

Are your mouse and keyboard connected to USB ports, or to the MiniDIN keyboard and mouse ports?

It may have to do with your power supply that does not ramp up or generate its power good signals properly to the system.

 

[rezzij]

Both are plugged into a PS2 port ... on the old motherboard, I could unplug them (with CPU off) and plug them into USB port - both would light right up even though CPU was off. I did not try it yet with new mobo.

 

[felixc]

You can verify if your BIOS has any sort of "wake-on" events that are enabled. ALthough very few people use it, there are features for a PC to keep some circuit sections powered, in order to wake-up the PC under certain conditions. Check if you can disable these things.

 

[bcastner]

The always on mouse is normal:

http://support.microsoft.com/default.aspx?scid=kb;en-us;325975