40X1 problem

[BITMOVER]

I have been involved with a project using the 40x1. Everything up to now seems to be on target. Yesterday when I powered up the protoboard the 40x1 has developed a problem. Some of the code executes properly, like the POST part of the code but other parts do not. With a processor exchange the software runs exactly as expected.

Reloading, or erasing and reloading the bad 40X1 produces the same problems. A simple 'turn on the pins' test has errors in the pattern. Is it posible that it has gone 'sour; and if so why. I would like to avoid this happening again. Everything is running off a clean and regulated 5V supply.

BTW: Is there ANY warranty on 'buggy' chips?
If anyone out there has had this problem, please join in!


Thanks

Len

 

[BeanieBots]

With no published diagram or code we can only guess at the cause.
Most probable, is over current/voltage on one or more outputs has damaged the output stage whilst leaving the rest of the chip intact. This has happened to several others and it has ALWAYS been a circuit error.
Please post your diagram so that we can take a look.

 

[hippy]

Simple output pin test patterns not working suggests a damaged chip, I/O pins burned out or damage done to the internal memory which holds the Firmware ( far less likely IMO ).

There's almost certainly the usual warranties for PICAXE but "buggy chip" wouldn't include damage caused during use which wasn't a manufacturing issue.

A circuit diagram, plus knowing exactly which pins have failed ( and whether stuck high, low or floating ) may help point towards how the problem arose. There are also unseen external events which can damage chips, static discharge etc.

It's also possible to wear the chip out although that would normally manifest itself as download errors. The 28X1/40X1 can usually sustain 100,000 erase cycles and often far more, you'd have to download near 300 times every day to limit it to a year's worth of usable life.