So as I mentioned in another post I have one of pca's tuner kits assembled. It powers up and doesn't explode or smoke but the empeg doesn't see it. I've checked it as far as the limited debugging notes of the assembly instructions go - the 5V and 9V regulators are indeed putting out the correct voltages. I have visually inspected my work a number of times and can't find any assembly mistakes. I'm certain the 2 or 3 parts left over served no real purpose

Now it would seem to me that the empeg should recognize the tuner if the path from the empeg to the PIC is alive. Looking at the parts list this would include the regulators, the MAX1489E level converter (IC5) and the PIC CPU (IC4) plus what ever clocks the PIC and resets it. What I don't see it which chip or transitor converts from logic-levels to RS232 (the 1489 goes from RS232 to logic-levels).

I know the schematic of the tuner can not be revealed as it is the property of empeg or whoever owns them now. But can anyone with knowledge of the design tell me if my assumptions in the above paragraph are correct? Likewise can anyone with a working tuner describe any test-points and signals that would allow me to narrow down the problem area? Aside from my DVM I also have a scope.

-- Craig