Oops! reversed power!

okay. I accidentally connected my power to the SSC-32 in reverse, for maybe 10 seconds. now the board doesn’t work. there was no smoke, and no physical damage, but the regulator got quite hot and the large IC was just slightly warm. now when i hook up power (correctly) the serial LED just lights up constantly, and doesn’t recognize any instructions. I am sending it instructions by TTL level serial using a Basic Stamp II, and it all worked perfectly before. is my board toast?

Have you tried connecting your ssc-32 to a computer and see if you can communicate with it using something like lynxterm?

I will try that, but I have never used lynxterm before, and i am quite new to SSC32 so i might not give you very coherent results.
Also, if this helps at all, I am using a Stamp Stack 2 (Parallax) to send it TTL serial instructions.
Also, I think it is a physical problem of some sort because of the heat, but i will try using lynxterm.

If the LED is lit then the regulator is probably working (you can see if you get 5v across the + and - pins on the board).

good point. but it is getting really hot. I haven’t been able to communicate with it yet. I don’t know what baud to use for the computer. also, i am using a 9v 300mA supply. is that too much power?

okay i got the baud rate set right. now when i hit the “Reg.” button, it gives me a message saying “can’t find ssc-32 card”. I don’t know what that means, but I’m guessing it’s probably a bad thing.

Did you check to see if you have 5V across the + and - pins?

The regulator getting hot sounds like you have a short on the board. Mispositioned jumpers on the ± pins or the VS2=VS1 pins might be something to look at. A blown/shorted capacitor might also be a suspect. Pull the VL/VS and ± pin jumpers and see if the regulator still gets hot.

Also, if your 9v power supply is not regulated, the actual output voltage may be significantlly higher than 9v when not under load.

I checked the board and there were no shorts, and once again there was no visible damage, so I doubt it would be a blown cap. if it is, i’m screwed because the caps are all SMDs, and i’m not that good at soldering. As for the VL=VS jumper, i had already removed that. I will try it out with a regulated supply and play with jumpers. I am running a bit low on time, so i have ordered another SSC-32. I know, it’s a big waste of money, but time is of the essence. My guess is that the reversed voltage bypassed the regulator, and fried the chip (it was quite warm), but i will still try your suggestions, and if it ends up working, i will feel terrible for ordering a new board. :wink: thanks for being so helpful. When i have time, i think i will try replacing the chip and then be more careful with power. I will post again when i have done the tests you have suggested.

by the way, i am not closing this thread in any way. This could be useful to people with the same problem, and it would be nice to get to the bottom of this.

Don’t feel bad about having two, if you get the first one working. Think of it as being one step closer to having two bots!