Newbie requesting help with tube screamer issue

[Scott97]

I just complete building the tube screamer from the general guitar gadgets site.

When I plug the input jack in completely I get no sound and and the LED doesn't light up.

When I back it  out halfway I get the LED to light but no sound.

I've gone over the parts layout about 5 times and can't find whats causing the issue.

Any ideas?

I used a 3pdt switch and a board I purchased from the site.

Thanks!!

Scott

[R.G.]

You have a hookup wiring problem. Hard to say what it is from that description, but there's a wiring problem there.

[petemoore]

Are you plugging half way in a stereo plug by chance?
 I don't multiply to conquer, I divide.
 I would hook a resistor to the LED and test which way around makes it light with 9V...polarity wise.
 I take the circuit board and test it:
 For continuity between + and - [should be 0]
 for ground at all ground points
 for V+ at the opamp
 Then test the battery voltage and compare that to every IC pin voltage to ground...
 NOGO?...if the voltages look to be outside the sweet spot [about 1/2 V for everything except pin 8 which is V+/9V, or pin 4/ground or 0v.] on a dual OA.
 Then on to the probing for signal loss stage of debug.  At this point something else will have been learned about the problem.
 The switch can best be sorted out using a DMM, after reading the article on bypasses at GEO.
 The tip of the input cable, inserted in the input jack needs to 'see' the circuit input on one side of the switch, as does the output side of the switch need to 'see' connect to the inserted cable output tip, DMM beep mode procedure helps find these simple routings, one at a time. Check for ground at cable sleeves.
 I've had chains fail as a result of:
 bad battery
 bad cable
 bad amp
 guitar pot scritch
 bad switch
 Each and every one of these items must work for the chain to be intact.
 First thing would be to eliminate or verify the input and output connections to board input and output.
  All grounds must be at ground.
 Then I'd test for short [+ &  -], battery voltage and start taking IC pin voltages readings from ground.

[the_badcliff]

I'm guessing you have the signal mixed up with the ground when you wired the input jack.

[Scott97]

Thanks guys!

I'll try out everyones sugestions and report back.

Scott

[mindwave_21]

A lot of the wiring diagrams for the jacks on GGG are mixed up.  You should refer to the faq here for the Ring Tip Sleeve hookup.  I had the same frustrating problem with my first build, which incidentally was also a tubescreamer.