Serial Programmer dead

[Ron Marcus]

Greetings list,
I am using the MElabs serial programmer. It worked great for years, until I plugged it in this morning. No green light. I checked all power connections and regulators, but it all tests good. I also get a "no communications" box from the PC I am working with.
Other than an 18F252 that decided to stop working, any ideas for trouble shooting?

Thanks,
Ron

[mister_e]

How about the Crystal?
Q1, Q2, Q3?

Possible to have a faulty DB9 cable?

Possible to have some break-link between the DB9 and the circuit?

Broken pins on the dip socket?

[CocaColaKid]

Do you have a way to check the com port? You might have a bad port.

[sayzer]

Or may be they inserted a secret timer/counter inside the programmer to terminate the life of it; and now it is time to buy a new one.

I am a great conspiracy theorist!

[Ron Marcus]

Sorry, I haven't checked the list in a few hours. I replaced the crystal, and checked the com port. I normally get the green light on power up whether it's hooked up to the PC or not. Does the chip do a diagnostic on the transistors on power up?

[Ron Marcus]

Otay... I spoke to Charles at MElabs. He told me that occasionally, the PIC252 just goes astray. About a dozen have, with no aparent cause. I ordered another chip and will update the list if this works. The board is so simple, I can't believe that it won't.
Thanks for the input,
Ron

[Ron Marcus]

Received the new PIC controller for the serial programmer. Fired it up, and that did the trick. Thanks for the input.

Ron