Pic kit 2 clone vdd short when troubleshooting

[be80be]

That's not what happens when the pickit comes on the the pin is pulled low or floating but the q6 is trying to power the vdd and it sends a error that somethings wrong with the vdd but don't belive me lol
You don't want power on when the pickit starts up without the 10 k to USB power it will give a error on vdd the p channel is on without the pull up and your are right in don't think it's good pick of parts myself it needs 5 volts to work right it not work lower the 3.5 like your saying but it still need to be pulled to USB 5 volts before the pickit powers on

 

[be80be]

R6 and d4 don't pull up if anything they hold it low lol

 

[Colin hoof]

Les I am not ignoring advice .I will however ignore you, if you keep posting inflammatory remarks and untruths about me. The information I have given has been accurate, but is of no use to me or anyone else for that matter, when it is ignored, misinterpreted and used to post contradictory, misleading, confusing and conflicted replies that don't help, in any way shape or form. Sing off the same hymn sheet or don't sing at all !!!

 

[Les Jones]

Hi Burt,
You make a valid point about the situation when power is first applied. I would have thought the firmware would allow enough time for Q6 gate to be driven high before reporting Vdd errors. I have no evidence that my thought is correct.

Les.

 

[Wp100]

A chance find, an old post just come to the top , seems to feature the same Pk2 circuit Colin was following , they could not get it to work either ..
See first and last posts, which has this circuit the OP says worked for him, copy below.
https://www.microchip.com/forums/m852928.aspx

 

[be80be]

If he makes the changes it should work the first thing it does is check to see if the vdd is powered by target and if there power you get a error but if you pull it up there's no error what's happening is its shutting it off so when the op powered the target it worked cause he had the thing powered witch works but if that pin doesn't shut off right it will not work right if you look at the real sch you'll see that what I posted is what it's looking to see.

 

[Colin hoof]

Hallelujah !!! Success at last the clone is working now !! I have had to forsake the variable vdd option however, for the time being anyway .Was not working at all with the op amp circuitry connected .The components will have to be changed, as suggested in previous posts, for this to be viable. Thankfully it is finally working, with no errors on connecting clone,before opening pic kit software. Passes all tests and outputting voltages as predicted.

A big thank you to everyone who has contributed to the completion of this build .Apologies to anyone I have offended along the way,but it has been a hard slog with little if no signs of it ever working as expected. Some learn by doing others just know instinctively. I wish I was the latter.

 

[Wp100]

Good to hear you have got it working, in part, though the variable Vdd not a major loss.

Would be interesting / helpful for others in the future to see your final circuit and components used, especially the transistors.

 

[mvs sarma]

Hallelujah !!! Success at last the clone is working now !! I have had to forsake the variable Vdd option however, ................ Some learn by doing others just know instinctively. I wish I was the latter.

perhaps i had assembled around 40 pickit2 through hole units. It is OK to learn while doing.
Instincts, i assume could go wrong some times unless backed by lots of experience. i do big mistakes despite my 40years of telecom experience.
all the best.

 

[Colin hoof]

The circuit used was this one in the end minus, the op amp circuitry connected. https://www.obddiag.net/prog/pickit2.pdf. The build albeit a little messed up, due to all the corrections made was built on a piece of vero board.The mosfets used were the same as the original circuit bs 250 and 2n5000 p and n channel mosfets. I only used,these as I had a shed load on hand.I haven't had much if any experience with mosfets, so thought it would be a good idea to use them in this design.It wasn't until the end of the build that their limitations and restrictive behaviour became apparent.

Please find enclosed as attachments pics of the final build.Also as an a compliment a zif socket board for programming all types of pic chips.