PICkit3 not working

[Ian.M]

An ICSP adapter is the easy option if your programmer doesn't auto-configure its ZIF socket. 

If you want to build one, take an 8 pin turned pin socket and use it as a header. Carefully strip, lightly twist, tin and trim one end of a 6 conductor 9" length of ribbon cable EXCEPT for the fifth wire which you should leave untinned and untrimmed.  Look up the ICSP pinout in the PICkit 3 manual and the pinout of any PIC12, and insert and solder the first four wires of the cable into the 8 pin socket accordingly.  The LPC (8 pin) PICs don't have a PGM/AUX pin + the cable needs a ground between ICSPCLK/PGC and ICSPDAT/PGD so carefully wrap the fifth wire round the Vss wire where it goes into the 8 pin socket and solder it.  Use the sixth wire for ICSPCLK/PGC. 

On the far end fit a 6 way 0.1" pitch female connector, swapping wires 5 and 6 to get ICSPCLK/PGC back to the right place and ground the PGM/AUX pin. Reinforce the header end with hotglue after everything is soldered and tested.

Be aware that your programmer probably wont be happy doing ICSP to any target that has other circuits connected to the ICSP pins, and if the rest of the board puts a significant load on Vdd or cant stand 5V, you'll probably need to isolate the Vdd to the rest of the board during programming.  Don't attempt to program with the target already powered.

Back to your faulty PICkit 3:  It sounds like U8 is blown.

IC SMT, 74LVC1T45 1BIT DUAL BUS TXRX SOT23-6
U8, U9, U11 TEXAS INSTRU SN74LVC1T45DBVR DIGIKEY 296-16843-2-ND

Raise a support ticket and Microchip should replace it quickly.  They may even send an advance replacement.   

Technically, the user replacing parts voids any warranty, but Microchip support normally don't bother enforcing that if any repairs are done competently and neatly with the correct parts so if you run into long delays or problems getting it exchanged, you may wish to repair it yourself.

Replacing U8 is highly likely to restore normal operation as long as the MCU I/O driving its DIR pin still toggles correctly when you swap the pin from input to output in the logic tool.  U8 is near the board edge 1/2" back from the pin 1 end of the ICSP connector J4. 74LVC1T45 is second sourced by NXP and Diodes Inc.

As a hack, you could get it going by stealing the 74LVC1T45 from the U11 position (near the other edge of the board about the same distance from J4) leaving U11 unpopulated.  This will disable LVP programming for any PIC with a PGM pin but it should otherwise operate normally.  You *MAY* need to link pads 2 and 3 of the U11 footprint to ground the LVP/AUX data line on the PICkit 3 MCU side to fool the firmware.

[NDani]

Hi to all,

Thank you for everybody for their valuable advice. In the meantime, Microchip recognized the case as a hardware fault and sent me a replacement programmer, which works fine. Actually, I'm quite amazed by the quality of service. The replacement unit arrived very quickly and I didn't even have to pay for shipping. So thanks to Microchip as well.