problems with pickit 3

hi everyone! i hope u can help me with this problem, im nuts about it! recently i've been trying to program a 16f877a pic, but without success, each time i verify, blank checking or program it shows me that some memory regions failed to verify/program/etc, when i read it the configuration word changes and i have to set it back to the configuration i want, i hook up everything correctly and the code is just to make a led blink





The following memory regions failed to verify correctly
Configuration Memory
Address: 00002007 Expected Value: 00002f09 Received Value: 00002fcf
Verify failed

Blank Checking...
The following memory regions failed blank check:
Program Memory
Address: 00000000 Expected Value: 00003fff Received Value: 00001400
Blank check failed

Check your voltages. Does the pickit need to be powered from your board? Do you have an excessively long cable?

i tried both, powering the circuit (only the pic and a led) with an external power source (set @5V) and powering with the pickit 3 itself, in both cases it failed, im using the original red cable pickit 3 contains

Do you always get the same memory locations failing on erase? Maybe you've just got a bad PIC.

yes always those 2 locations, i have tried 3 different 16f877a pics and same result, i even tried to program them in another PC and still failing! maybe a blown pickit?

it happens to me sometime ago but try and upload the pickit OS again restart your system and try again....

kabeer i just did what you said and it didnt work at first, but after a few tries its now wokirng :S im totally puzzled, im afraid it will fail again soon, thanks a lot to both kabeer and barry for your replies and help! i really appreciated it

- - - Updated - - -

fuck! see this now

Programming...
The following memory regions failed to program correctly:
Program Memory
Address: 0000000e Expected Value: 00002012 Received Value: 00002010
Programming failed

- - - Updated - - -

now it's stuck in that memory location...

Programming...
The following memory regions failed to program correctly:
Program Memory
Address: 0000000e Expected Value: 00002012 Received Value: 00002010
Programming failed

Programming...
The following memory regions failed to program correctly:
Program Memory
Address: 0000000e Expected Value: 00002012 Received Value: 00002010
Programming failed

Programming...
The following memory regions failed to program correctly:
Program Memory
Address: 0000000e Expected Value: 00002012 Received Value: 00002010
Programming failed

Programming...
The following memory regions failed to program correctly:
Program Memory
Address: 0000000e Expected Value: 00002012 Received Value: 00002010
Programming failed

- - - Updated - - -

recently ive tried writting an only 3 lines code, but when i see the program memory there are others "ghost" instructions, and if i read the pic memory a bunch of instructions come out!

hi Anthony,
I fear , it is a case of Vpp failure in PICKIT3
if it has facility to calibrate and Trouble shoot like PICKIT2, better perform those tests and be sure tn at you get your Vdd as close to at least 4.7V and Vpp at least 11V.

Then , if you are using too high electrolytic caps across the target, better remove them. Later perform an erase and then test for blank.

hi mvs sarma! thanks for your reply, could you pls tell more about those tests? im getting nuts with this problem!

- - - Updated - - -

i found some in google! ill be giving results soon! thanks once more

ok! i tested the voltage in vpp nduring programming and it reaches 13.01 volts... i think its ok

It is Good

please check Vdd also infact it is Vtarget. it should not drop below permitted min value. Let us see
All the best

Have you tried to contact Microchip's technical support? They're generally pretty good.

barry said:

Have you tried to contact Microchip's technical support? They're generally pretty good.

Click to expand...

you are right barry !!
perhaps they could check it remotely also if a permission is given to reach the pc and set it right.
Microchip is known for good support and at times they replace the programmer itself.

vdd is @4.75 volts, ok ill give it a try with microchip support! i'll be giving result soon, thanks once more guys!