Ruined U2 Programmer?

[rsocor01]

Also, the U2 programmer has some sort of short circuit protection built in, and I know that by experience . There was one time I was programming ICSP in a circuit that had a short in the power lines. Nothing happened to the U2 programmer, but the USB port got broken. Luckily, I was using a USB hub and that was the only thing that got fried.

Robert

[Amoque]

Well, to close this thread I will relate my findings.

With Darrel's help and assurance from Robert that the programming device should still work, I began exploring my issue.

Even with the corrected software and code verifying, I had problems as before. No amount of frustration seemed adequate to resolve the issue. From my research it seems that none of the chips would sink current, unless another pin was in use - except, when it would (I know, but really... this is how it appeared to be). My 'scope - an old one, but freshly calibrated - showed only a 3V drop between pin HIGH and pin LOW (verified by the faint glow of LEDs alternately connected). Yes, except when it was a 5V drop and all worked as it should. It was very frustrating to be so inconsistent.

As an alternative to chewing off my thumb, I tried another new chip - number five. All the four previous with the same issue, a mix of 3 16F88 and 1 12F683, oddly working and driving (or not) LEDs on different pins.

Johnny was right - number 5 is alive; every issue is magically corrected.

For my farm I cannot understand how... Chips that have worked perfectly and were put away carefully, packed in non-conductive foam and in a non-conductive box (from my favorite cigars) were fails of exactly the issue of those I had exposed to damage. I tell you frankly, had any of you explained the issue I could not believe the truth of it, and yet...

Now I do not know whether to investigate my neighbors for some unauthorized death ray pointed haphazardly or to search in the basement for fear my wife has nuclear waste stored without my knowledge. Or perhaps it was some intermittent USB or programmer issue (the electronic one, not the burned curtain, missing one eyebrow from fire one) that will haunt me again in the future. At this point, one answer seems as likely as the others.

[mtripoli]

Before you close the thread...

Did you try turning off Capture/Compare/PWM?

CCP1CON = 0?

To the point of not pulling down to 0 volts on the pins, turn off global pull-ups:

OPTION_REG.7 = 1 (1 is disabled).

[Demon]

Don't close a thread. You never know if more posts will be useful. Admins only close threads that get out of hand.

Robert