PIC doesnt Program correctly

[sandeepa]

Hello all

I was using this PIC16F877A chip and it would program correcty using WinPicProg.
Today all of a sudden,the chip isnt programming correctly,I am getting verify errors at different locations,every time I try to program it.Alos it wont erase correctly.
I am using the same board which was till yesterday correctly programming the same chip.I am getting 5v and 13V correctly.
What could be the problem?

Thanks.

 

[Nigel Goodwin]

Hello all

I was using this PIC16F877A chip and it would program correcty using WinPicProg.
Today all of a sudden,the chip isnt programming correctly,I am getting verify errors at different locations,every time I try to program it.Alos it wont erase correctly.
I am using the same board which was till yesterday correctly programming the same chip.I am getting 5v and 13V correctly.
What could be the problem?

The usual cause is the 13V supply, is it from batteries - they could be running low, or if it's from a mains supply it may be marginal, with too much ripple on the supply. A meter could well read 13V, but a scope might show that it's dropping below that.

 

[The Real MicroMan]

If your using a bread board, the contacts might not be making contact, check continuity to all programing lines

 

[phalanx]

Tis the season for increased static electricity too. Could you have zapped your PIC? It has happened to me before!