New problem with PiCs Icd2Clone.

[Pigi_102]

Hi all,
after some succesful debugging session with the ICD2 clone, yesterday I got a relly strange problem.
I've attached the ICD2 to the computer and windows did not recognized it.
I' ve said " No Problem, I have to check if something has changed to the drivers" but it was all correct.
Then I've reflashed the 4550 as sometime the firmware get lost.
Same problem after the reprogramming phase.
I've checked if there were something wrong under the board as I didn't change nothing either on the board than on the XP.
Everything was ok.

What I've noticed is that the 4550 get really hot.

After several test in reflashing either the 4550 than the 877A it startsworking again without change on the board and on the windows side.

The really difference is that the board was really cold at the beginning of the tests as it was in the lab that has no way to get some hot air and the temperature was 8 degrees celsius.

Could it be a problem with crystal or similar at low temperatures ?
Wich are the things that I could check if the 4550 get hot ?

Pigi

 

[are]

I think there is some problem whit the power or the ground.

Maybe you can check what is the current for the ICD2 when hi is cold and than you can look if the current is changing when hi comes hot.

You can also check the voltage on all the pins of the 4550 and than connect a resistor of 100 ohms over for ballast (than you can see if there is a connection).

 

[Pigi_102]

Are,
first of all thanks for the reply.

Second, can you please explain better what do you mean.

For what I have understood I should check how many amperes ( or mA ) are drained when the board is cold and how many when he is running, from the usb connector, am I right ?

For this this of resistor it isn't clear to me where I should put the 100 ohm resistor. Do you mind to make it more clear ?

Thanks in advance
Pigi

 

[Pigi_102]

I did some more test yesterday, and have noticed that when I plug the icd2, it doesn't get recognized ( and that was obvious ).
The worst thing is that when I read the content of the 4550 (with a programmer, not the icd itself ) to check if is still well programmed I see lot's of difference .

Basically it seems that when plugging the icd, something happens in the circuit that put the micro in programming mode and then something other change it's content.

This could happens if the pic goes in programming mode and there is some kind of noise on the RB used to programm it ( or the pins are left "floating").

Now I wonder why the pic goes in programming mode, and where there could be the leak that make it hot.

Any idea ?

Pigi

Added after 1 hours 26 minutes:

In effect there is no chance the 4550 goes in programming mode.
Anyway I have added a resistor to MCLR and reprogrammed again with the MCLRE enabled.
Now it works again, so I start to suspect some problem with my usb ports.

I'll keep you informed of any change.

For the moment thanks to all.

Pigi

 

[are]

Just for info, when you put a voltmeter to a ic pin an you add a resistor, you can see if there is enough current (direct connection to vcc or vss)