Tonepad sansamp gt2 debug.

[jmdfd415]

Ok I just got done building the gt2. I have checked all wiring and components to make sure it was right and everything looks fine. I am getting no sound out it. Here is the layout http://tonepad.com/getFile.asp?id=112    Here are the readings I am getting from the ics and tranny.

Battery: 9.19

IC1-4 are all getting the exact same reading
1: 9.19
2: 9.19
3: 9.19
4: 0.00
5: 9.19
6: 9.19
7: 9.19
8: 9.19

Q1:
E: 9.19
c: 9.19
b: 9.19

Obviously there is something seriously wrong.  I have  went along the ground rail and everything connected to it is reading 0.  Any help is greatly appreciated.  Thanks!

[Meanderthal]

 Good Lord... That shouldn't  even be possible... unless you shorted every single pin to pos. somehow...

Did you accidentally push the hold button on your DMM?

[jmdfd415]

Yeah I have no clue whats going on. I have checked and all traces and solders look pretty clean.

[heyniceguy]

it looks like your 1/2(V) circuit is farked and it's causing all your Vbias points to be shorted to 9V. I'd check your Vbias voltage divider.... sheesh does it smell funny yet?!

[jmdfd415]

It doesnt smell and its not even getting warm or anything. Can you tell me where the vbias is?

[petemoore]

 Probably two equal value resistors strung across the PS Rails.
A voltage divider like this would make 1/2v = Vbias.
  See FAQ.

[jmdfd415]

Ok I have been messing around a bit and fixed a few bad solders. Now I can hear a clean guitar sound coming though then really loud bassy noises and ticking.

Here are the new readings:
IC1
1:4.58
2:4.58
3:4.15
4:0
5:9.20
6:4.58
7:4.58
8:4.15

IC2
1:4.65
2:4.65
3:4.55
4:0
5:9.20
6:4.58
7:4.58
8:4.58

IC3
1:4.52
2:4.52
3:4.50
4:0
5:9.20
6:4.52
7:4.52
8:4.50

IC4
1:4.58
2:4.58
3:4.58
4:0
5:9.20
6:4.58
7:4.58
8:4.58

Q1:
E:3.93
B:4.58
C:9.20

So any ideas?

[tjcombs]

I'm no expert, but the voltages on the tranny look off to me. I could be wrong......   

[jmdfd415]

Any idea what it should be?

[jmdfd415]

Anybody?