PICKIT2 problem "Verification Fail"

Thread Starter

pekka123

Joined May 18, 2017
5
Hello there!

I try to find fans of PIC-micros and Pickit2.
I have some problem with my clone Pickit2. I have also original PICKIT2 and PICKIT3 (because some PICs do not program any more wirh PICKIT2).
I have made my PC Start device (http://remotesmart.wikidot.com/pc-start) some times, but about two days then PK2 says after programming "Verifying Fail".
And it really program badly to my board, I tried my software.
I tried to start my PC (Win10) again, no help.
Then I tried with old XP, no help.
Then I tried to change my PIC (PIC16F88) at my board, no help.

Then I tried with original PICKIT2. Yes, it worked ok. I programmed without power.

Then I open PICKIT2 (fail one) and using Tools/Troubleshoot I tested the PK2. Everything was right.
Then I looked the Tool/Calibration and it seems to be right (4.00V).
I donwloaded a new operating system, no help.

In the programmer there are two 8 bit memory chips (i2c 24LC512). Can they be somehow wrong?
There are some electrolytic capacitors also, is any body found them faulty?

The device is only two/three years old.
Also I looked the 5 pins to CPU, but they seemed right.

The programmer chip PIC18F2550 can be also bad, but it accept a new sowfware.
Can sombory suggest other methods?

Pekka Ritamaki
 

Thread Starter

pekka123

Joined May 18, 2017
5
Hey again.
I find the PICKIT2 probem (Verification Fail).
It was a capcitor C15 (47uF).

When I measured it, it was shown "no capacitor".
When I take it open, the other end of the capictor was cut.
I am not sure it it went cut, when I open it, but after I replaced it with 10uF capacitor the programmer worked perfetctly.

The only thing was that I used normal capacitor, not SMD.
I must add a tape to other end of PICKIT2 to keep plastic cover on the place.

Pekka Ritamaki
 

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jjw

Joined Dec 24, 2013
551
I dug up an old HP laptop with XP os and Pickit2 clone, which has worked before with another PIC:s
Tried to program 12F683 with internal oscillator, power from Pickit2 and getting this Failed to program at address 0x0000.
Any ideas?
I tried three chips and the third succeeded. Maybe faulty Pics?
I once ordered a few from China.
 

jpanhalt

Joined Jan 18, 2008
10,203
I had a similar problem ( PK supplying target) years ago with a PK3 and 12F683. Sometimes worked; sometimes not. Answer was to put an additional decoupling cap between GND and VCC. That came about after discussion with Microchip people in Chandler, AZ. Don't remember the value. Maybe 1 uF or even a 10 uF tant. The power supply in the PK3 is really wimpy. No experience here with PK2.
 

jjw

Joined Dec 24, 2013
551
I had a similar problem ( PK supplying target) years ago with a PK3 and 12F683. Sometimes worked; sometimes not. Answer was to put an additional decoupling cap between GND and VCC. That came about after discussion with Microchip people in Chandler, AZ. Don't remember the value. Maybe 1 uF or even a 10 uF tant. The power supply in the PK3 is really wimpy. No experience here with PK2.
Thank you.
Anyway it was my error.
The config was wrong. Had to enable MCLRE
 

jpanhalt

Joined Jan 18, 2008
10,203
Thank you.
Anyway it was my error.
The config was wrong. Had to enable MCLRE
Really? My understanding is that enabling MCLR is only needed if it is used as a reset.

According to Microchip, you can use that pin as a digital input and still use it for programming VPP. There are some caveats, though.
1) It is sensitive to what is attached. That is, any sort of load will prevent the rapid change needed to initiate programming.
2) You need to disable low voltage programming (LVP) to use it. (The 12F683 does not have LVP.)
3) Years ago I was powering target by a PK3 and had a problem when voltage was set at 5.0. Lowering that voltage a little to 4.75 made the problem disappear.
4) Upon searching for issues with that pin, I found that with PICKits there is a setting to make VPP high before VCC (recommended) vs. setting VCC first. I use ICD3 and have never looked for or touched that setting.

In practice, unless I am really short of pins, I enable MCLR and do not use if for an input.
 
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jjw

Joined Dec 24, 2013
551
Ok. I will continue testing.
It might be an intermittent error.
I have now the chip in a diy 8 pin adapter and will put a cap between Vcc and Gnd.
 

Ian Rogers

Joined Dec 12, 2012
804
Just as a side note... I had a time where the use of pickit2 was haphazard.. T'was a cheap USB lead... I bought a quality one and still use that lead.. As its always the mini plug, I have three leads, one for each programmer I have....
 

jpanhalt

Joined Jan 18, 2008
10,203
I was just coming back to edit my comment.

According to Microchip MCLR does not need to be active (ON) for ICSP to work. However, if you search the Microchip forums, you will find lots of ICSP programming problems related to using it as an input. It can be very sensitive, and how sensitive depends in part on the programmer. The ICD3 can put out 100 mA compared to the PK3, which at best seems to be about 20 mA.

That is why I just turn MCLR ON, use a weak pull-up of 10 k, and don't use it as an input unless absolutely needed. Some people recommend 20 k for the pull up to protect other parts of the circuit from spikes in VCC.

EDIT: Another problem is putting a small cap (0.1 uF ceramic) on MCLR. Early on,Microchip recommended that to protect against noise from effecting a reset when MCLR was"ON." Datasheets for later devices recommend against it. If it is not recommended in the datasheet,I don't do it. If it is recommended, then I may or may not use it, but I keep it in my checklist if I have problems programming.
 
Last edited:

Thread Starter

pekka123

Joined May 18, 2017
5
Hey again.
I find the PICKIT2 problem (Verification Fail).
It was a capacitor C15 (47uF).

When I measured it, it was shown "no capacitor".
When I take it open, the other end of the capaictor was cut.
I am not sure it it went cut, when I open it, but after I replaced it with 10uF capacitor the programmer worked perfetctly.

The only thing was that I used normal capacitor, not SMD.
I must add a tape to other end of PICKIT2 to keep plastic cover on the place.

Pekka Ritamaki
I dug up an old HP laptop with XP os and Pickit2 clone, which has worked before with another PIC:s
Tried to program 12F683 with internal oscillator, power from Pickit2 and getting this Failed to program at address 0x0000.
Any ideas?
I tried three chips and the third succeeded. Maybe faulty Pics?
I once ordered a few from China.
JJW
There are many reasons, why PICKIT2 can't work.
I understand that you have got PICKIT2 to verify your PIC, but then it doesn't write right.

1. Try to read old PIC. It it read right, then I think that your PICKIT2 is right.
2. If it doesn't read right, take your PICkit2 open and look the connectors to pins.
Look carefully, that they are in good connected by loop.
3 . Look with PICKIT2 program, the Troubleshoot.
Check with the voltmeter, if all the voltages are right.
Expecially try to measure the voltages at PIC RB7 and RB6.
It may be difficult, but it nesessary to do.
4. If you have other PICKIT2 it is easy to change it.
5. Then you must look carefully to inside of the PICKIT2.

Regards Pekka
 

jjw

Joined Dec 24, 2013
551
JJW
There are many reasons, why PICKIT2 can't work.
I understand that you have got PICKIT2 to verify your PIC, but then it doesn't write right.

1. Try to read old PIC. It it read right, then I think that your PICKIT2 is right.
2. If it doesn't read right, take your PICkit2 open and look the connectors to pins.
Look carefully, that they are in good connected by loop.
3 . Look with PICKIT2 program, the Troubleshoot.
Check with the voltmeter, if all the voltages are right.
Expecially try to measure the voltages at PIC RB7 and RB6.
It may be difficult, but it nesessary to do.
4. If you have other PICKIT2 it is easy to change it.
5. Then you must look carefully to inside of the PICKIT2.

Regards Pekka
Thank you.
It looks like it is working now.
The Vdd voltage was a little bit low 4.7V if that was the reason.
After calibration 4.9V
 
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