All,
Picked up a broken PW-2120 locally, and after repairing the rotary encoder (pcb had just broken off), I can't get the unit to output anything.
controls all mostly work (couple LEDs seem defective, or their driver is mis-behaving), but other than that, the unit seems okay on visual inspection. I've contacted the company for schematics, but their initial response was just the plain manual (disheartening).
If anyone has one of these, I have a couple questions.
One, is "U1" populated, and if so, by what? It seems odd it would be missing, as it's labeled "U1". =/
Two, on the front PCBs there are a few jumpers. Is there anything on those? Also, the 7805CV on the unit gets pretty darn warm pretty darn quickly. Making me think something is drawing excess current. The only thing I see heating up is the CLC522, which is socketed, on the main board. Appartently that's a variable gain amplifier. I don't see anything really coming in, or out of it on the scope.
Thanks for any help. I'm going to tear it down more this weekend and see if anything jumps out at me.
Interestingly, the Frequency counter aspect of the unit works perfectly. So, I can assume the oscillator (where ever that is, I can't find it) is working.