I am a user of the PICKIT2 programmer about 15 years.
I have repaired it few times.
In April 2023 it stopped to program my test board.
It was a chess clock, but I am waiting for PCB.
I started the programmer fully again. No help.
I used Tools/Troubleshoot. Every thing seemed to work, but I can't load my file( Hex).
Showed error.
Then I used other project which used the same CPU PIC18F2620-I/P. It doesn't worked.
Then I started the CPU again. No help.
I went to other computer with the same prototype, but no help.
Then I took my other programmer, which was PICKIT3.
I needed to reload PICKIT2 Tool, (Hex-file) because it was doing with Microsoft PICKIT3 tools.
I loaded it in PICKIT2 files.
Then it loaded my Hex-file and also programmed the CPU.
I didn't test it, because now I know, that PICKIT2 board is not working.
I measured it with Troubleshooter and measure programmer pins.
I found, that when I turned ICPDAT pin to 0, it doesn't go, it was about 4.5V.
The ICPCLOCK pin went to 0V and 4.5V when they were asked.
I open the PICKIT2 board and started to measure the last transistors.
They were Q4 , PNP transistor (failed) and Q3 the other working transistor.
I took the new PNP transistor and changed it.
When I measured the board, I did not get a connection to PIN 4 in output connector.
Then I remember that I have replaced 33R (R20) resistor.
It has been broken last time and I have replaced it with wire.
I did a new small wire from Emitter of Q4 to pin 4.
Then everything seemed to work with the ohmmeter.
I tried to operate the Programmer, but it doesn't worked.
I start a new program and now it worked!
7 days later this kit went again to failure.
The same pin doesn't work to 5V after I had checked it with the tools.
I open and find a small open at pin 4 connector.
I repaired it and it worked again.
I had not found this second failure when I measured the PNP-tansistor.
==
Error 10.9.2023
I was doing my old Post radio reception.
It has PICF88 and 4*20 LCD.
I want to change timer1 to configure time.
Not worked.
I looked old tips, but no one helps.
I started the programmer once again. No help.
I open the programmer and looked open soldering joints.
No help.
What was faulty?
Then I changed Device Family from PIC18 to Midrange.
Well, it helped!!
==
Again my PICKIT2 started not to work.
A open it and find almost all connector wires broken.
It took long time to repair it, but I decided to put a new connector.
I found from my normal place TME ,a good 6 pin 90 deg connector.
It costed only 0.14e/pc, but I have to buy 5 pieces minimum.
I made an order with 10 pieces and they came from Poland after two days.
Now my PICKIT2 works like a new one.
==
At 2023 October my PICKIT2 stopped to work
I used Tool, but it doesn't help,
It said that VPP error, but the VPP was there 12V, when I measured it.
Then I used my other PIC programmer PICKIT3.
It need to load a new operation system, but then it worked.
I started to check what is wrong in other programmer.
I measured volts in programmer
Then I started to draw schematic of PICKIT2
When I tested VPP ( 12V) , VDD doesn't start.
I looked double FET ( N and N Fet).
I tried to open Fets by putting resistors from gate to ground, but it was difficult to see what happen.
I use oscilloscope.
Then I soldered PIC18F2550 pins 1-8, because they seemed a little open.
The next day I have other works, but when I finally started to test the programmer, it worked!
I do not know what was open pin in processor.
I did an order a new PICKIT2.
Then it it went broken again next day.
I measures all the connections.
It was a big job.
Finally I found that from two Fet U5 the wire to diode D4 was broken.
I can't find it because it wan not in upper plate , or not in down plate.
I put a small wire to it.
Then it worked!
Here is the error in picture, but it is impossible to see, because it was in middle PCB layer
javascript:;
A new problem
At 27.1.2024 I was making two similar Can-products.
The other board was programmed well, but other not.
I looked with the microscope all connections and measured all the voltages, when I was testing PICKIT2 with Tools.
Everything seemed right.
I have used a new PIC18F26K80 device from the same source.
I read Internet PICKIT2 errors and one says that input capacitance can't be more than 0.1uF
I have 1000uF and PICKIT2 worked with other board.
I took it out and try to measure it with my new meter which has up to 2000uF range,
The new meter worked only al smallest range 20nF, but it showed too much.
Then I looked my switching regulator and found lot of frequency with my scope an it should be,
Then I looked the VDD, which was about 5.3V as it should be.
But there was a terrible oscillation!
I took other SMD 1000uF 16V capacitor and oscillation stopped and programming succeed.
Here is a schematic
Using PICKIT2- or PICKIT3- programmer, the PICKIT2 do not have to take the big capacitor out!
http://kair.us/projects/pickitminus/
==
At 21.4.2024 one PIKIT2 went broken.
I replaced it with other.
Then tested it and found that pin 1 doesn't give 12V, but 4.96V,
I looked the schematic and open it.
I saw that C15 ( 47uF elco) was open mechanically, maybe when it was dropped to ground.
I put it back, It was a normal rounded 10uF capacitor.
I tested it and it worked.
At May 2024 I was doing my levelmeter.
It has CPU PIC18F2431 and it worked normally.
But then I have red indication and the PICKIT2 software said the the device not detected.
I try to find a fault in circuit, but everything seems a normal.
Then I tried other circuit board and it worked normally.
I start the program, no help.
I start the computer, no help.
The I looked Youtube https://www.youtube.com/watch?v=4JVNHfxp4MY&ab_channel=Programbrain
It says that do not use VCC ( pin2) in PICKIT2.
I took the pin 2 off an put 5V on my card and I could program like normal,
Why the VCC pin is so important?
I must as my Finnish friend, who is done PICKI2-.
At May 12 2024 I got a new problem.
My Pickit2 seems to load a new program, but it doesn't go in to PIC.
It actually go with green light, but when I try to read it if was full with 0xFF.
I have PIC18F2431 in smd version. I tried with a new PCB, but it has a different PIC.
It worked fully,
Then I go to other PC and other but similar PICKIT2 minus program.
It doesn't work any better.
Then I took a new PIC18F2431 an made a new but similar PCB.
It doesn't work any better.
Then I took a new PIC type PIC2620 and tried it only (in SMD programmer) and it worked.
Then I took old PIC18F2431 off an replaced it with PIC18F2620 in a new PCB.
It worked!
Then I took a new PIC18F2620 and took from real PCB the PIC18F2431 off an replaced it with a new PIC18F2620
It worked, but what can be a reason, why a new CPU doesn't work, but the other PIC work?
Then this PIC started to go the same thing. I programmed it many times and finally it started right.
Then I measure with troubleshooter VCC. It was 4,75V, it should be 5V.
I try to increase the power supply, but it was 7.4V.
Then I found that the current limit was on!
I increase it, and my PICKIT2 started to work normally.
==
Again came problem. I took my old PIC18F4431 pcb and I made to program to it.
I went right on.
But when I tried to correct program, it doesn't go on and PICKIt2 said that it is not working.
I find one help file form Internet.
It said that took pins 23-25 off and try again.
I took them off.
I doesn't not help me.
I has 0.1uF capacitors on both side of LM78L05.
I took the CPU off and put it on separate 40 pin programmer and I worked.
But what was the real reason?
I tried it again in PCB many times with the external power and without the power.
i doesn't do a new program, but my program worked.
Pekka moc.liamg|odg3ho#moc.liamg|odg3ho
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