How do I know if a PIC is dead ?

[rngd]

Hi,

How do you guys test to see if a PIC is burnt ? Im using a PIC16F877A with the WinPic800 programmer. The programmer can detect, read and write onto the PIC as usual.

The reason I ask this is because I accidentally connected around 8-10V into the Vref pin of port A, and Im worried that I might have fried it. It was only for a very short while though, like for one second..

Also, will only certain ports be dead, or will the whole PIC be dead ?

Thanks everyone.

[skimask]

Hi,
How do you guys test to see if a PIC is burnt ? Im using a PIC16F877A with the WinPic800 programmer. The programmer can detect, read and write onto the PIC as usual.
The reason I ask this is because I accidentally connected around 8-10V into the Vref pin of port A, and Im worried that I might have fried it. It was only for a very short while though, like for one second..
Also, will only certain ports be dead, or will the whole PIC be dead ?
Thanks everyone.

I would think that what you did wouldn't kill the PIC...and if it did hurt it, it's probably just that particular pin/port.

In my experience, killing an entire PIC is fairly hard, especially the 16F series. I think I've killed one PIC in the last XX years, probably due to this lightning strike that went from my finger tips to the PICs pins after walking across a carpet.

[Archangel]

Hi rngd, If you have a suspected dead PIC try erasing it several times, this sometimes works.

[rngd]

OK, so I guess its probably not dead then. Thanks.

[Squibcakes]

Rngd,
For times like these (suspect RIP pic) I load it with a very simple LED blinky program which flashes all the ports on and off. If that works than I know that the pic is OK.
;P

Squib

[skimask]

Rngd,
For times like these (suspect RIP pic) I load it with a very simple LED blinky program which flashes all the ports on and off. If that works than I know that the pic is OK.
;P
Squib

Amazing how it always goes back to ol' blinky isn't it?

[mindthomas]

Amazing how it always goes back to ol' blinky isn't it?
Ya.. It's a good basic beginner, and testing code :)

[falingtrea]

If you did something to the Vref pin, you only may have messed up the analog circuitry. I would do an LED check of the specific pin you overvoltaged. Also was the voltage directly on the pin or through a series resistor? The resistor would have probably protected the pin.

[Ingvar]

Overvoltage with no current limiter is more or less a bulletproof way to fry a pin on a pic. I've never seen the entire pic beeing fried from it though.