ICD2 Problems

[spuffock]

Problem with ICD2, whatever I try, I get the following problem. Firstly a failure to get the chip ident (most of the time), followed by a rock-solid "cannot enter debug mode". Using the ICD as a programmer, I am not sure if it writes anything to the target, because while reading it seems to erase. The Vpp line pulses to +13 volts.(during read ??)
I have tried a random selection from 3 PC's, 3 versions of MPLAB, and 4 different target processors. Results always much the same.
It would be good if someone lives near enough to me to try my ICD on their system, to see if the results are similar.
It seems likely that either 1) I've done something stupid, 2) I,ve stupidly not done something, 3) something bad has happened to the IDC.
Out of ideas. Anyone help?

 

[3v0]

To start with check out a few general things that can cause problems. (check for the easy things) If you do this and answer these questions we will be better able to help you. Please do answer all the questions.

Which kit/PCB/schematic did you build it from ?

PC to ICD2
If using serial port have you turned off the FIFO buffers in the PC?
If using a USB to serial converter that may be the problem.
Does the busy lite on the ICD2 ever come on?
When you switch for a PIC16 to PIC18 (MPLAB config) does it download a new OS without problem?


ICD2 to Target
Most failure to enter debug mode is due to the target not having a working clock. Most often due to a misprogrammed config. Try a good PIC and set the config to use the internal OSC.
Is the cable between the ICD2 and the target six inches or less?

More when above is checked out and answered.

 

[spuffock]

icd genuine microchip not kit worked last month!
usb
busy light comes on
says it downloads operating system ok
cable is short enough
clock is running but I cant change the config
other info
says it programs ok but says chip is blank if read
known good program does not run in target
Vpp line pulses to 13v during read

 

[3v0]

It is rare to find someone here with the real thing. Could be a lot more helpful if it were a clone.

Before you open if up I would give Microchip a call. I have heard that they are very good about replacing defective units even out of warranty.

I had a problem where the ICD2's (Inchworm) PIC (16F877A) had a weak drive on one of the pins used by the MCLR line. Replaced the PIC and it worked. It worked fine for months prior to failing.

If not the ICD2 PIC itself then I am thinking the problem is with circuits between the ICD2 PIC and the ICSP connector. Time to dig up a schematic. I found one using Google in Eagle format but it would not load.

Most of the clones are based on **broken link removed**
He describes how the MCLR, CLK, and DATA lines are driven. Not sure but I would think that the action if not the circuits have to be close to what the original is supposed to do.