Two PIC 16F877A fried in two days!

[manumenzella]

Hi. I was working on a small 4x4 led multiplexed display. I connected the programmed PIC to the circuit, and it was brought to life. Some programming later, I, once again, put the PIC into the socket and NOTHING! I could still program the PIC and verify it, but the PIC would just sit there doing nothing!
I realized that I was overdriving some pins (trying to source 60 mah!!!)
So, next day, I went out, bought another PIC, and some hours later, the same thing happened!!! I realized that the problem was that when I insertid the PIC, only for a brief moments, the pins were connected in the wrong way, and the PIC was dead. Now here is my question:
do you guys turn of the programmer or the cirtuic before inserting the PIC??
Since that moment, I do disconnected, and I have not fried another PIC!
Thanks
Manuel

[malc-c]

do you guys turn of the programmer or the cirtuic before inserting the PIC??
Since that moment, I do disconnected, and I have not fried another PIC!
Thanks
Manuel

I think you've answered your own question there

[sayzer]

...or the cirtuic before inserting the PIC??...
Manuel

Did you actually insert the PIC into a working circuit?

Or you just thought how it would be?


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[Acetronics2]

<< do you guys turn of the programmer or the cirtuic before inserting the PIC?? >>

Hi,

Generally, a circuit does what it wants at power up ...

so, your programmer MUST be quiet and powered a while before inserting a device !!!

Only logical ...

Alain