Help me with a very deep dive into the Aiwa PL77, PL777, & PX710

These three models are the same- and the p75, p705, px610 all use the same board and chassis. i have at least a half dozen of each of these- which i am only telling you to point out i checked inside more than one of each to compare


I have a 610, 710, and a 77 that all are missing 'dsl 2' (but dsl 1 and off work)

and the 710 and 77 both have an issue with the sound starting ok, but becoming rough/crackley after a few moments.


i was going through everything with the help of @Silver965 who is incredibly knowledgeable when i came across several things that don't make sense or don't match the manual.


the first thing on the front of the board is C91 which is in the manual board layout by the photo eye. (green)



the second thing is an additional capacitor to the left of C59 & C60




then, on the back, there are two resistors not shown in manual above r66 (and these are also on the px610)





anybody got any clue whats going on?

 

And C91, a capacitor, is directly connected to the motor IC it seems?

 

Hello starting from the px 610 diagram the C90 is connected on one side with R 107 and on the other with R 106... and the C90 is not where you indicate






... Looking at the printed circuit board on both sides ... starting from R107 (Red) and following the green track You arrive at the C90 and R106 ..

 

always on the px 610 circuit ..
in the photo where you indicate an additional capacitor on the 610 circuit there are none of the three and the transistors connected to them are also missing ...

 

@Silver965 I am talking about the px710, pl77, and pl707

 

And i am talking about c91

 

px610 C90 = px710 C76

 

Sorry for misleading post, see title... this thread is not about the 610, just noting the 610 is based on the same chassis and board but missing the led ic and plss. i've found a few other minor differences.

 

sorry but at the beginning we were talking about the 610 and I got a bit confused