cupcake problem

[TreeSlayer]

well, it seems i built a great gospel station reciever. when i plug everything up and touch the #3 post on the level pot, i get gospel music. nothing else works. any thoughts?

[midwayfair]

http://www.madbeanpedals.com/forum/index.php?topic=902.0

We need more information to help.

[TreeSlayer]

gotcha! i'm testing some things now. i discovered that R6, 470k, is reading 211.9k. it's marked the same as R3 and R4, that are reading 461k and 459k. CHECK THEM BEFORE YOU INSTALL THEM!!!! very valuable lesson here! still checking others. thanks for the link, midwayfair!

[midwayfair]

gotcha! i'm testing some things now. i discovered that R6, 470k, is reading 211.9k. it's marked the same as R3 and R4, that are reading 461k and 459k. CHECK THEM BEFORE YOU INSTALL THEM!!!! very valuable lesson here! still checking others. thanks for the link, midwayfair!

Resistors can read differently when in-circuit.

That will not be causing your entire circuit to fail. Keep searching. Take voltages before desoldering. That will narrow down the problem.

[PimpMyTone]

Like Jon said , resistance will read differently when in circuit if there are other resistances in the same circuit .
In that case 211.9 k looks normal .

Start by taking voltages of each pins of the ic and the transistors .

[madbean]

Can we have a pic of your build? Have you loaded it into an enclosure or are you testing it on a breadboard, etc? Reason I ask is are you sure you have grounded everything properly.

[TreeSlayer]

Can we have a pic of your build? Have you loaded it into an enclosure or are you testing it on a breadboard, etc? Reason I ask is are you sure you have grounded everything properly.

here ya go! i think everything is grounded proper...

[TreeSlayer]

here's another, just in case....

[TreeSlayer]

Like Jon said , resistance will read differently when in circuit if there are other resistances in the same circuit .
In that case 211.9 k looks normal .

Start by taking voltages of each pins of the ic and the transistors .

i've checked every pin on the bottom if pcb and i have voltage of some degree at all of them.

[TreeSlayer]

back side of pcb... i've checked this under a 10x mag glass and there are no short circuits.

[TreeSlayer]

Like Jon said , resistance will read differently when in circuit if there are other resistances in the same circuit .
In that case 211.9 k looks normal .

Start by taking voltages of each pins of the ic and the transistors .

i've checked every pin on the bottom if pcb and i have voltage of some degree at all of them.

sorry... i was gettin a little antsy there... here's the readings i got...

[midwayfair]

Something's very wrong in the biasing, power, or ground of your circuit. You should have 9v on pin 8, and about 4.5v on pins 1, 2, and 3. Pins 4 and 5 should be ground -- you seem to have some voltage leaking into your ground.

[TreeSlayer]

Something's very wrong in the biasing, power, or ground of your circuit. You should have 9v on pin 8, and about 4.5v on pins 1, 2, and 3. Pins 4 and 5 should be ground -- you seem to have some voltage leaking into your ground.

that sounds serious. i guess the only thing i can do is start over...

[jkokura]

It is serious, but starting over is not the next step. Analyzing the data just tells us what's wrong, not the next step.

You have power leaking to ground? You should stop the power from leaking to ground. The first step to do that is to find out where power is going to ground.

The usual guess here is that you have a solder bridge between any of your 9V connection points and and of your GND connection points. Luckily, this is a small circuit, so there aren't many of either. Start to examine all of them closely, and even reheat those pads carefully with your iron. Once those pads have been isolated from each other, you may have a working circuit.

Jacob

[TreeSlayer]

It is serious, but starting over is not the next step. Analyzing the data just tells us what's wrong, not the next step.

You have power leaking to ground? You should stop the power from leaking to ground. The first step to do that is to find out where power is going to ground.

The usual guess here is that you have a solder bridge between any of your 9V connection points and and of your GND connection points. Luckily, this is a small circuit, so there aren't many of either. Start to examine all of them closely, and even reheat those pads carefully with your iron. Once those pads have been isolated from each other, you may have a working circuit.

Jacob

thanks, Jacob! just starting to get a tad frustrated. i've looked this over several times and can't see anything shorting out. i'm going to try reheating the pads.