You really need an oscilloscope to check accurately but a DVM will give some clues. If it still doesn't work, try measuring the voltage from VSS to VDD and from VSS to VPP while it tries to program. The PIC can be programmed in two ways, by high voltage on the VPP pin or using normal VDD and driving the LVP pin, if you use the wrong mode it may not work. If the wiring is already short, try connecting the LVP pin as well. In this picture am using a 4.7k resistor, you’ll be powering the circuit with the PICKit pin 3 of the PICKit is ground. So, to use old boards thas has Pickit 3 header with Mikroprog programmer, you definitively need an adapter to have the signals on the same order. Try to keep the wiring as short as possible, the programming is performed by sending high speed serial data through the ISCP pins and they are not forgiving of long wire lengths, up to about 10cm should be OK. The pinout of the programmers are shown on the next image: on the left side, Pickit 3 pinout and on the right side, Mikroprog pinout: You can find more technical info about these programers here and here. Without it the PIC or LED or both could be damaged and if present, the extra current while programming may drag the supply too low. ![]() ![]() ![]() The connections look correct but if you really do have an LED on RA0 you MUST fit a series resistor to limit it's current. In normal operation a capacitor may be useful as a filter or to delay the reset but while programming it can delay the rise of VPP and stop the device going into programming mode.
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