One of my chips: No propeller chip found on any serial port. Any hope?

ionymous

When I try to "Identify hardware..." with Propeller Tool, I get the error window:
"No propeller chip found on any serial port"

I have it wired up on a breadboard with the minimal setup, just power, reset, and tx/rx for the prop plug.
I've tried two other propeller chips in the same setup and they work fine. So I'm convinced it's just the one chip, not a breadboard, cable, or pc problem.

Is there anything I can try to revive my apparently bad chip?

LoopyByteloose

Well, if two other Propellers work fine in the same board... prospects of the one that failed are poor.

But if this is a 40pin DIP package, you may have bent or broken pins on the corners and that might include the Pin 30 and 31. With a little tender care, you can either solder a salvaged pin over a broken or a bit of 20 gauge wire. Bent pins may be folded completely flat and never reach a socket.

Cluso99

I am presuming you have all power and ground pins connected and BOE as well? Do you have bypass capacitors too?

ionymous

I AM using the 40 pin dip package, but I don't see any bent or broken pins.

I only had one Vss connected and one Vdd connected. I tried connecting both Vss and both Vdd but that didn't help.
I also tried connecting only "the other" Vss and Vdd pins (in case there was something wrong with the ones I normally use), but that didn't help.

BOE is grounded.
As for "bypass capacitors", I assume those are capacitors on my power circuit. Yes.

Out of curiosity, is there any pin on the chip that I could connect +3.3v and hurt it?
At this point I'm worried about how I hurt my chip, and I don't want to put a replacement chip into my more complex breadboard until I am sure I won't hurt another one.

Mike Green

1) You must have both Vss and both Vdd pins connected to their proper voltages. If you don't, the chip occasionally can become damaged. The symptoms are that the chip can be programmed and programs that use one of the internal clocks (RCSLOW or RCFAST) will work normally, but the PLL on the crystal oscillator doesn't appear to work.

2) You should not apply voltage (greater than 0V) to any pins before Vdd and Vss are connected to a proper power supply. This is true for almost any CMOS IC, not just the Propeller.

3) The most common reasons for a Propeller chip to be "Not Found" are: a) No power or improper power to the Propeller chip; b) Something wrong with the serial connection to pins 30 & 31.

LoopyByteloose

One Vss and One Vdd is a disaster waiting to happen. With all Propeller chips, all power and ground lines need to be included and protected with capacitors on each pair.

I know there are a lot of schematics out there that abreviate the wiring... but that is the real wiring.

Reverse polarity is a sudden death contidion == +3.3 to ground and ground to the normal +3.3 supply.

Toby Seckshund

Not wishing to encourage any experimentation, but I did give a Prop the wrong way around treatment. It did have the relative luxury of the voltage reg in the path which might have current limited. Outwardly it looked as if I had got away with it, until I ran Turbulence on it, with this Prop there was a horizontal glitching of the title at the start, everything else was OK.

9 Volts is a killer, I've tested one for that, and yes it had to be another chip.

The only times that I have had the "No Prop found ..." were due to the TX and RX paths being the wrong way around (using the PC's real serial port) or the attempt of using an AVR USB -> '232. That one I think had timing issues that the Prop wouldn't handle, a FTDI chip worked as expected.