[PIC] My pic16f628a suddenly stopped working. Dead?

[burrow]

Hai,

my pic16f628a suddenly stopped working. I placed in my pickit 2. but i got the error saying Vdd voltage error. i tried applying external power and the kit started detecting the mcu, and it shows writing success but when i read it again its all empty.

I know the programmer is working, because iam able to program other mcu properly

 

[paulfjujo]

it seems you get many problem with MAX232, with MCU ...
what about your power supply 5V DC ?
and how do you connectICSP to PIC ?
are you programming in situ ..(on the final board) or only with the MCU on a breadboard ?

 

[burrow]

Yea friend.. many problems really.
Actually it is my first major project where in i will be taking some water level inputs and feeds the pic16f628a, this then transfers data to pic18f4520 where in actual decision taking takes place, like deciding which pump to turn on. is their any warning etc.
Everything was almost done. and last thing i remember is accidently connecting mclr pin directly to ground and i think only after that it stopped working.

iam doing things on final pcb. Everything was working good (except an i2c lockup issue ) before this mcu stopped working

- - - Updated - - -

Anyway iam going to get new mcu tomorrow,
hoping everything will go well

so by the way will connecting mclr to ground directly, kill the mcu ?

 

[betwixt]

Connecting MCLR to ground will only reset the PIC unless you have MCLR tied to something that might be able to deliver a lot of current. Grounding it while programming will short out the VPP generator in the Pickit and that might cause damage.

You haven't accidentally set it to Low Voltage Programming (LVP) mode and left RB4 in programming mode have you?

Brian.

 

[showmesomeluv]

Always try to test the input voltage and current coming from the other sources in PCB, if problems occurs remember the simple Ohms Law, Voltage / Resistance = Current

 

[burrow]

Hey i just recieved a new MCU,
and found that problem is with my programer. iam using pickit 2 clone,
When i program my pic18f4520 it works really fine.

But it fails to program my16f628a.
it says writing success but when i try to verify it says verification failed, and when i read i only get full zeroes.

when i perform erase, and then read then i get all 3FFF but again when i try to write something it turns to full zeroes.

i tried external power also..
also icsp to my board and using the programmer board given to me.

i checked mclr voltage and it touches around 11.5v peak

 

[betwixt]

Sounds like you should have invested in a real Pickit2 which has programmable VPP.

The programming spec says VPP must be between 10V and 13.5V but must also have a rise time of 1uS or less. You probably are not meeting that specifcation.

Brian

 

[burrow]

Sounds like you should have invested in a real Pickit2 which has programmable VPP.

The programming spec says VPP must be between 10V and 13.5V but must also have a rise time of 1uS or less. You probably are not meeting that specifcation.

Brian

But strange thing is that i was able to program it once or twice 2 or 3 days back.

And also iam still able to program my 18f series without any problem

 

[mvs sarma]

clone, do you mean one made by some one like. "supreme electronics"
or
A semi design without Vtarget adjust facility etc?

try to place a crisp photo or a link to the clone, so that some one could suggest means to overcome the problem.