Took board out of bag, attached board, burned out board. What did I do wrong?

Hey all-

I have (had) a Mesa 7I76D attached to a 6I25 card in my computer that I think I burned out. At least, it no longer lights up and I saw smoke and I'm guessing that is bad.

While I've been trying to follow along with various instructions/videos/etc, I don't understand where it went wrong. I have a 24V power supply that is connected to field power on the 7I76D, along with a single driver (a StepperOnline DM542T). I plugged in power and immediately the 7I76D started smoking. I had enabled 5V power on the 6I25 so there were lights on when the 24V power was applied to the board, but even with the power cables removed no lights come on, so I'm taking that as a dead board.

I'm really new to all this so i guess the most basic question is, what did I do wrong? I quadrupal-checked the wiring before I applied power, which wire goes to ground, which is hot, etc., using the guide mentioned elsewhere in the forums here (that nice PDF of various wiring states). I also checked the manual and all seemed okay. The only guess I have is that I can't have the power supply providing power to both the board and the driver (which also takes 24V).

I ordered a new 7I76D but before i try to plug that in, if anyone can point me to where I went wrong I'd greatly appreciate it; burning out boards gets expensive quick.

Ron

Things can cause smoke in a 7I76D

Reversed field power polarity
> 36V on field power

5V supply issues:

6I25 and 7I76 have mis-matched cable 5V settings:
6I25 set to supply power and 7I76D not set to accept 5V cable power
or 6I25 set to not supply power and 7I76D set to accept 5V cable power

>5V supplied to external 5V connection

I think that may have been the issue; I had set the jumpers on the 6I25 to supply power (W1 and W2 set to ON), but I had not set either W1 or W2 on the 7I76D; they were still set to their defaults. Re-reading the manual I think this is covered on Page 2.

Assuming I set the jumpers correctly on the new 7I76D, I should be able to have the one 24V power supply drive both the board and the one driver though, right? I have two power supplies, and was wondering if I was going to need a separate power supply for each driver, along with one for the board.

The field power can come from any source
(its completely isolated)

You do need to make sure it does not exceed 36V under any circumstance