MXR Micro Amp, from General Guitar Gadgets.

[markbee]

Thank you for advice ill try that right away. So you think that the circuit from general guitar gadget might not be right?

[markbee]

So the problem is that its not grounded properly, when i took out the guts signal was coming through it was all buzzing and there was recognizable reaction to the guitar but it was coming through, i put it all back carefully and made sure that the jacks do not touch te enclosure and the problem is still there, nothing changed when i tried to switch the yellow and the red one on the imput jack. When i checked the continuity between jacks and enclosure and it is on. What now? at least i know whats probably causing all of that.

[FlyingZ]

It's possible that schematic is from a 30 year old version but I somewhat doubt it because some things just don't jive. I suggest not referring to it as a MXR Micro Amp clone.

[markbee]

thanks but that does not quite solve my problem

[twabelljr]

Are the symptoms still the same? No bypass, no led and no effect? I keep focusing on the bypass because that is the most simple part of the signal circuit. Just a path around the effect, and should be the easiest to debug. The led should light up when the effect is engaged without a signal circuit so that is a whole different issue. It is possible your switch is faulty like Mark mentioned earlier. I guess it's time to follow the debugging thread and post your voltages and maybe something will point in a more helpful direction. http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

[markbee]

Connect one end of your meter to the tip of the input cable and make sure there is no continuity to ground (the enclosure or the cable sleeve)

I just did that and found out that there is a continuity. What shall i do with that? Wiring of the Jacks is correct.

It is possible your switch is faulty like Mark mentioned earlier.

Due to the continuity test Ive made the switch shouldnt be faulty.

Ill post the voltages as soon as I put in the new IC, i havent done that yet, I try to focus on getting bypass signal.

[alparent]

Maybe one good picture of the inside (with the board out of the way) so we can follow the wires.
Or take it out of the enclosure.....anything to help us follow the wires.

[markbee]

http://imageshack.us/photo/my-images/194/fotografie0672.jpg/

Ok here it is, i hope it helps, Im sure its wired exactly like his http://generalguitargadgets.com/pdf/ggg_mamp_lo.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a
but the grounding is wrong somehow.

[FlyingZ]

Sorry about that, I was a bit tired. What I was thinking is possibly it is a diy design flaw. The original has a 100 ohm on the 9v in into a 100uf to ground cap. Plus I misread your post and thought it was just a hum problem 

[twabelljr]

When you are in bypass the switching is setup to ground the input of the effect. Make sure in bypass mode that you do not have continuity between the top left (yellow) and top right (black) terminals of the 3pdt as shown in your last photo. The wire strands and solder look pretty close. Or you can remove the other jumper on the switch (black) to eliminate the input ground for now.

[markbee]

there is no continuity but also when i bypass th circuit there is no continuity between top right (red) and middle right (yellow) and it shall be there if im not mistaken?

[twabelljr]

I am calling "top" as the way it is seen in the photo. So what you are calling "middle right" yellow I would call "bottom middle" so we are on the same page. So the way I am looking at it I would say bottom middle yellow and bottom right red and they should have continuity in bypass, yes. That is the path to the output jack from the red jumper from the input jack lug. In the GGG diagram they are top and middle right. 

[markbee]

I see. So it looks like it might be faulty switch after all?

[alparent]

Download this PDF and look at the 5th page.

http://www.tonepad.com/getFile.asp?id=76

Notice the orientation of the solder tabs on the switch (make sure your using the same poles)

I would redo the wiring.

[twabelljr]

Looks like the same wiring as the project file, just different pins. http://generalguitargadgets.com/pdf/ggg_mamp_lo.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a Better yet, follow this: http://gaussmarkov.net/wordpress/thoughts/wiring-up-a-1590b/

[markbee]

Ill try that, but im affraid ill be having difficulty wiring the pcb to the circuit, since I not really sure where is something supposed to go becouse of my lack of experience, but ill see thanks

[twabelljr]

Is the circled part of your switch as curved as it looks? If so, I would say it was definately overheated and should be replaced. The wiring diagram you followed is correct. Your pcb connections are labeled, take your time and you shouldn't have any problem rewiring a new switch. It looks like you had it wired correctly. Trim of the ends of your switch wires and strip them back a bit and start fresh, with a new switch, one lug at a time and let them cool down between each one.  In the photo I can now see that your jacks are wired correctly. With the wires out of the old switch you can test it for continuity to verify it is bad.

when i bypass th circuit there is no continuity between top right (red) and middle right (yellow)

You pretty much verified it is bad here. Each middle lug should have continuity to the one above it in one switch position and the lug below it in the other switch position and read OL to all of the other lugs. (with the lugs horizontal)   

[alparent]

Just an observation. Why are those jack isolated from the enclosure?
Don't we want that enclosure grounded...not the power jack, but the input/output ones?

[markbee]

they arent any more, i just put the paper thare to make the wiring more visible on the photo, ok Ill try to change the switch and let you know

[markbee]

Ok so i switched the 3dpt for a new one, nothing at all has changed at all, same continuity results, no bypass sound. Only thing that probably happened was that i might have eventually burnt the switch that was alright before. Im starting to get hopeless