rocknroller
Active Member
Looks like you have good audio out of AN377 and into AN363 pin 2. need to make sure the VCO as part of the PLL is oscillating correctly.
If the voltages on the AN363 are wrong against the schematic and the data sheet, then it is probably this part, but you have to make sure it is not one of the passive comps.
Pin 12 should show the 19KHz osc.
Refer to the datasheet http://www.datasheetspdf.com/pdf/610174/MatsushitaElectric/AN363N/1
Socket the AN363 part and try a new one.
I believe I am mistaken about there being good audio coming into AN363 Pin 2. I now don't see anything there (or out Pin 6 from AN377). This may be my ignorance of using a scope but I don't see any obvious signal there at all. With my scope set to 5V/div, 1ms, DC coupling (? should this be on?) and probe set to 1X, I see a audio signal at pin 13 (meter circuit?) of AN377 (same audio I confirmed with audio tester at that point) . I don't see any other obvious audio on any other pin now with the scope (swore I did in earlier tests with the other scope but maybe I'm confusing receivers)
What should my scope setting be on with respect to voltage, time etc? Should I be 1X or 10X on my probe?
Shouldn't I be seeing something at Pin 1 and Pin 8?
Another interest point, I remeasured all voltages at that chip
Pin1 2.2
pin2 2.2
pin3 2.2
Pin4 - ground
pin5 1.5 (muting off)/1.57 (muting on)
pin6 5.8
pin7 4.2
pin8 5.7
pin9 5.7
pin10 5.7
pin11 17 (***This subjectively seems very high)
pin12 5.1
pin13 2.8
pin14 ground
pin15 5v
pin16 0