Muzzle won’t power on

[Rando_calrissian]

I just finished the build but it won’t power on where should I start?

 

[fig]

What is voltage at pin 5 of LT1054?

 

[Rando_calrissian]

What is voltage at pin 5 of LT1054?

-4.2

 

[fig]

Double-check the key jack wiring.

 

[Rando_calrissian]

I followed the picture and the other forum post talking about it I believe it’s correct I’ll check again though

 

[Rando_calrissian]

Double-check the key jack wiring.

Checked it over again and the key wiring is correct

 

[music6000]

Checked it over again and the key wiring is correct

Did you use TRS Jacks for key chain?, they look like mono jacks

 

[Rando_calrissian]

Did you use TRS Jacks for key chain?, they look like mono jacks

Yes I used the ones linked on the bom page

 

[music6000]

Do you get Continuity if you put DMM test leads on solder switched tip & tip terminals on Sidechain jack?

 

[Rando_calrissian]

Do you get Continuity if you put DMM test leads on solder switched tip & tip terminals on Sidechain jack?

Yes

 

[Rando_calrissian]

I still can’t figure out why it’s not working. Anyone have a voltage list at junctions I can compare to

 

[zgrav]

list the voltage readings you are getting on all of the pins for the ICs.
also confirm which IC pins have continuity to ground

 

[music6000]

list the voltage readings you are getting on all of the pins for the ICs.
also confirm which IC pins have continuity to ground

Bofore going any further, Clean the PCB & Inspect your Solder Joints, very Questionable!

 

[Rando_calrissian]

Ic3
1-8
-.02
-.02
.001
-2.637
.002
-.013
-.013
8.66

Ic1
1-8
1.989
4.646
.005
-3.096
-6.61
2.558
1.392
8.68

ic2
1-10
-.262
-1.385
-.836
-.332
-.285
-.404
-1.619
0
0
-2.615

11-20
8.67
-.287
-.286
-1.648
-1.62
0
-.295
-.411
-.259
.003

 

[music6000]

Ic3
1-8
-.02
-.02
.001
-2.637
.002
-.013
-.013
8.66

Ic1
1-8
1.989
4.646
.005
-3.096
-6.61
2.558
1.392
8.68

ic2
1-10
-.262
-1.385
-.836
-.332
-.285
-.404
-1.619
0
0
-2.615

11-20
8.67
-.287
-.286
-1.648
-1.62
0
-.295
-.411
-.259
.003

The voltages are all over the place, Clean the board & check for Dry joints & Bridging, ie solder jumping onto another pad.
This is critical when buiding these circuits to Clean the flux residue off the PCB.
It will show any dodgy solder on the pads!
I use Electrical Contact Cleaner in a Spray Can on the Solder side directly.
You can use it in conjuction with a Toothbrush if you have trouble cleaning though it has not been needed with my Builds.

Cheers music6000

 

[TSReppe]

Cleaning, reflowing them clean again would be my recommended first thing to do. If that doesn’t work I’d say it’s audio probe time. How are your skills at reading schematics?

 

[Rando_calrissian]

Cleaning didn’t help anything but one major problem I see is that q2 is not receiving 9v from the rail as it is supposed to

 

[Rando_calrissian]

Cleaning didn’t help anything but one major problem I see is that q2 is not receiving 9v from the rail as it is supposed to

It is getting .709 on the collector and .156 on the emitter

 

[music6000]

It is getting .709 on the collector and .156 on the emitter

What voltage are you getting at Pin 5 on the LT1054 ?

 

[Rando_calrissian]

.156

What voltage are you getting at Pin 5 on the LT1054 ?

.156vdc

 

[music6000]

Pin 5 goes directly to the Collector of Q2.
What voltage is at Pin 8 of LT1054