Can you post some pictures?
Check 485 chip near terminate jumper
If last unit in DMX string, make sure terminate jumper is present
Make sure remove for wireless jumper is not removed
Make sure terminate resistor is the 120 ohm resistor
Examine pic socket solder joints to make sure there is a lead coming through all holes (pin not bent under on socket)
Check voltages to make sure regulators are not swapped. The '485 chip should have 5 volts on one of the pins and the pic should have 3.3. I don't have a board handy, can someone tell us which pins those are?
Good luck!
RM
Deanna has the units back in her possession, and she'll need to provide pictures.
We did check both 485 chips, swapped them, swapped them back. we know the chip is good, and we've verified that the legs are not bent.
We did NOT enable DMX termination. this was a test bench setup, and we did not have multiple items on the DMX bus -- only a USB DMX dongle, and then the unit under test. All 3 failed in this configuration, while our 2 working units continued to work in this same configuration.
checked the colors of the resistors, and they matched the working units.
didn't check the sockets/board connections for bent pins... but this is unlikely the cause for 3 units having identical problems.
We did not check the regulators... unfortunately. didn't know the pins and expected voltages... but in hindsight we could have compared to the working units.
It sounds like the first thing to test is the data link led... though I don't understand why a LED in reverse would prevent channel control -- i'd expect only the LED to be off.
The second thing is to test voltages on the regulators. Having more info on specific pins and voltages will help Deanna to make these checks.
Thanks.
