strange error with microcontroller

[superchiku]

i bought this new atmega16 which worked great until this day when i tried to progam it i got this unusual error

device signature invalied : 0xffff

i checked my power supply and connection and everything seemed to be allright, i used another mcu in its place and it worked great with the same state of connections and power.

Have i blown this microcontroller??

[Admin]

Lower the programmer ISP frequency to something really low. If the AVR is set to a low frequency, but the programmer is set too high, you could get invalid device signatures.

[superchiku]

no the frequency is right coz i programmed another mcu using the same hardware,no problems whatsoever

only this one gives problem

[benji]

if the whole thing works by trying another similar micro then propably your atmega16 is blown up,,,
did you change any fuses that you dont know about?

[superchiku]

as i told bfore the changes in the fuses were similar with both mcu wone works another doesnt so i guess its just gone