Greetings, all! Long-time lurker, finally taking the plunge! I bought a GGG Bosstone kit. Assembled it, and naturally it doesn't function. ;D I get guitar signal through bypass, but engaging the switch kills all sound.
So I did due diligence, studied the troubleshooting pages here on DIY Stompboxes, and a few other links. Took my digital multimeter, set to volts, started probing all the connections. Made notes in preparation for providing as much information as possible when I ask for help. HOWEVER - I noticed that the readings on one end of some components don't come close to matching the readings at the other end. For example, on a .022uF capacitor, one end reads 7.37, and the other 1.29.
Before I post up all my numbers, could somebody please tell me if this might be an expected result, or if I'm doing something wrong or stupid?
thanks in advance!!
if you had the same voltages on both sides of the component, it would be shorted (ie a normal wire)
the transistor voltages are where to start
edit: did you see ggg has sample voltages?
Q1
Collector
5.3v
Base
0.6v
Emitter
0v
Q2
Collector
0v
Base
5.3v
Emitter
5.9V
thanks for the info. I didn't notice that data before; I shall investigate it further.
So, on a related note, then, if I'm getting the same values on both ends of a resistor, does that indicate a short someplace? (I'm trying to find out how much information is too much vs. not enough before I ask for specific help. Thanks for your understanding!)
First, here is a link to the schematic: http://www.generalguitargadgets.com/pdf/ggg_jbt_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a (http://www.generalguitargadgets.com/pdf/ggg_jbt_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a)
Here is a link to the board layout: http://www.generalguitargadgets.com/pdf/ggg_jbt_lo.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a (http://www.generalguitargadgets.com/pdf/ggg_jbt_lo.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a)
I made no modifications to anything: I used all parts supplied and made no substitutions.
Okay, here are the readings:
Voltage at the circuit board end of the red battery lead = 8.11
Voltage at the circuit board end of the black battery lead = 0
Q1
C = 6.9 (expected voltage: 5.3)
B = 2.18 (expected voltage: 0.6)
E = 1.70 (expected voltage: 0)
Q2
C= 1.70 (expected voltage: 0)
B= 6.89 (expected voltage: 5.3)
E= 7.37 (expected voltage: 5.9)
D1
A (anode, the non-band end) = 1.29
K (cathode, the banded end) = 1.7
D2
A = 1.7
K = 1.29
Please help me learn what all this means, and what my next steps are in troubleshooting this! Thanks again!
E = 1.70 (expected voltage: 0)
this is the first thing you need to take care of. "0" means it's grounded, which yours isn't
....and Q2C is also grounded
Thanks for helping me, Lucifer.
So... how do I then make those connections grounded? Do I need to unsolder and then resolder? Is there a break elsewhere in the circuit that I need to uncover? I'm not trying to be annoying... I really have no clue.
Okay, with LucifersTrip suggestion, I embarked on solving my non-grounded transistors. I found a cheap-o magnifying lens and started looking over my board. I expected to find soldered connections touching where they shouldn't, but was pleasantly surprised to find all my joints clean and bright silvery... until I saw the connection for the ground wire on the board. THERE WAS NO SOLDER AT ALL! I had somehow missed that connection.
A quick minute later, an application of solder... and sweet sweet fuzztone!
So, maybe a noob problem, but I'm glad it wasn't anything more complicated.