[BUILD] 1176 Rev A - Back to the beginning...

[weiss]

i guess you found the problem.

- none of the light yellow points reach ground. i guess bad solder point at the ratio board.
- wiper has continuity to main pcb as well as the ccw leg, but they also have continuity to each other (e.g. when i check ccw against wiper or 15 against 17...) bridge?

 

[scott2000]

- none of the light yellow points reach ground. i guess bad solder point at the ratio board.

circuit ground???.......  does pad 16 on main pcb connect to pad 16 on ratio board and ccw leg of output pot????? and negative of input transformer. center tap of power transformer.....etc.........

try rotating switches and checking??


and you need to be aware what kind of meter you have when checking continuity.....some have settings.......I can set my Fluke to show continuity past a certain resistance and, if it's set too high, I can get continuity everywhere.......

 

[weiss]

no ground at all. there is no connection to the ratio board.
my meter said OL (overload), otherwise i'd get no audible signal with a value shown

 

[scott2000]

try rotating switches and check?


I think I may have messed up and confused things more with the ground comments.... sorry..... :-[ I didn't look at the entire schematic as a whole yet......

I need to  try to make more sense of how the switches interact in relation to ground.........

 

[weiss]

no worries! using switches didn't change things. but what i found out: cable going to 16 on main pcb had a bad solder point. i'm gonna have to repair that.
what i don't get, why do wiper and ccw leg of the output pot always show a connection throughout the test points? are points 15 and 17 on main pcb allowed to show continuity?

 

[scott2000]

are points 15 and 17 on main pcb allowed to show continuity?

try rotating the output pot and see if it changes that

 

[weiss]

sorry you're right, it was turned completely cw  :

 

[scott2000]

cable going to 16 on main pcb had a bad solder point.

Was it not making connection to ratio board????

 

[weiss]

Was it not making connection to ratio board????

no it didn't.  was a loose connection

 

[scott2000]

that would create some problems

 

[weiss]

that would create some problems

indeed. now it's correct. continuity where it belongs.

 

[scott2000]

So do you have circuit grounds from the output pot and ratio board???? Like this I think????

 

[weiss]

So do you have circuit grounds from the output pot and ratio board???? Like this I think????

yes correct! i just turned on my unit, still not compressing, output/ input works correct.

 

[scott2000]

And these points are right????

I'm guessing yes...

 

[weiss]

And these points are right????

I'm guessing yes...

yes

 

[scott2000]

and you are sure pad 4 on ratio board isn't touching one of the output pads.....It looks like you cleaned it up at some point.....just checking....

 

[weiss]

and you are sure pad 4 on ratio board isn't touching one of the output pads.....It looks like you cleaned it up at some point.....just checking....

no connection there

 

[scott2000]

With gain reduction on, does Pad 22 show continuity to circuit ground???

With gain reduction off.....no continuity???

and what is this? just a loose piece of shrink??

 

[weiss]

With gain reduction on, does Pad 22 show continuity to circuit ground???

With gain reduction off.....no continuity???

and what is this? just a loose piece of shrink??

pad 22 on meter board or main board does not show ANY continuity to ground as it appears.. ???

oh haha that one got lost in the wilderness... already removed  ;D

 

[scott2000]

pad 22 on meter board or main board does not show ANY continuity to ground as it appears.. ???

Regardless of Gain reduction switched  on/off?


Is the ground from meter board showing connection to main pcb??? and all the other ground points in circuit??