Cannot overwrite P89V51RD2 microcontroller

[nikhilele]

i have got 30 used 89v51rd2
when i am trying to load the my program its not responding
but when i am using free chip it is working but with those 30 i am not able to program the chip.

I am using Flash magic for programming

 

[ckshivaram]

complete the word RD2???? BN or FN
FN has a batch problem ... their bootloaders arent working.............

 

[nikhilele]

Most of them are BN only few are FN

 

[ckshivaram]

which one has problem? you did not specify.........

 

[nikhilele]

both are having problem all 30chips
i observed in few some program is there as in my development board for few chips leds were blinking

 

[ckshivaram]

try to use an external progammer and see if it works.... or read the hex file in all chips???? more over what error you get??? put the snapshot to see......

 

[dimas_lilik]

It happens also to me.
I try to check the result when the programming voltage is too high.