Classic II bomarc audio schematics

[marcelv]

Can someone confirm the bomarc schematic for the classic II is wrong regarding pin 1 and 2 of the DFAC?

wrong version (pin 1 connected to pin 2 and swapped)



corrected version


Second question
where does the via next to C11 go

 

[marcelv]

checklist I used for the audio repair on the classic II rev A board

C3 47uF 16V
- gnd
+ R2, R7, R15

C4 47uF 16V
- phones switch
+ pin 5 U1

C5 10uF 16V
- gnd
+ pin 8 U2 (78L08), R21

C6 10uF 16V
- gnd
+ R6 (4k7 to R15)

C7 10uF 16V
- gnd
+ pin 7 U11 , R33

C8 10uF 16V
- gnd
+ pin 3 U1

C9 1uF 50V
- pin 10 DFAC
+ R29

C10 10uF 16V
- mic in
+ pin 3 U11 , R7

C11 10uF 16V
- gnd
+ pin 2 DFAC


pin 1 DFAC is connected to R32 , R37


C12 10uF 16V
- R35 , U11 pin 6
+ pin 6 DFAC , R40

C13 47uF 16V
- gnd
+ pin 1 U12

C14 10uF 16V
- gnd
+ pin 1 U2 (78L08)

C15 1uF 50V
- pin 12 DFAC
+ pin 13 DFAC , R37

 

[smrieck511]

Incredibly helpful. Thank You!

 

[btb]

Having just reverse-engineered the whole thing, I can confirm that error on the DFAC. The via next to C11 doesn't go anywhere, this board is littered with such dead-ends. Presumably test points.

 

[smrieck511]

Wait...I'm confused. Are we saying the C11+ to DFAC pin 2 on the schematic is incorrect or just that via? Sorry if I'm slow on this...I just double checked the continuity of all the caps...I didn't have continuity from C11+ to DFAC pin 2 (I checked it six times). No visual sign of a broken trace under a microscope. I do have audio but was wondering if it was perhaps a bit low. I ran a bodge wire but curious if anyone knows what that particular break might affect or if that's what we're talking about when we say the schematic is wrong? Should I remove the bodge?

 

[JC8080]

Wait...I'm confused. Are we saying the C11+ to DFAC pin 2 on the schematic is incorrect or just that via? Sorry if I'm slow on this...I just double checked the continuity of all the caps...I didn't have continuity from C11+ to DFAC pin 2 (I checked it six times). No visual sign of a broken trace under a microscope. I do have audio but was wondering if it was perhaps a bit low. I ran a bodge wire but curious if anyone knows what that particular break might affect or if that's what we're talking about when we say the schematic is wrong? Should I remove the bodge?

If you haven't already, look at btbs other post where he links to his redrawn schematics.

 

[smrieck511]

Should be connected.

 

[btb]

I just double-checked it and yes, it should definitely be connected.

 

[smrieck511]

I just double-checked it and yes, it should definitely be connected.
View attachment 87191

excellent. Thanks.