MicroAMP problem

[Outtagetme]

Hi guys,
this is my first post here but I've been reading you a lot!
So, I built my MicroAMP clone, as per GGG's layout, but now I have a strage problem. When i put everything in the box (an Hammond painted enclosure) no sound comes out. When I disconnect the input jack from the case and let it hang freely, everything works. I put it back, and nothing works.
I checked all the wiring and the components, all the solders seem good to me..now I don't know what to do.
By the way, the input jack is stereo (although I wanted to put a mono there since I don't need battery).
Any help would me much appreciated!!

Greetings from Italy,
M.

[rousejeremy]

You have a grounding problem. Is your input jack wired like this?

[bukas]

your signal is lost in enclosure (ground), or there is no connection to ground

check your wiring, especially input ring-sleeve-tip  if you used stereo jack

some pics would be useful

[Outtagetme]

You have a grounding problem. Is your input jack wired like this?

Yes, except for the part connected to the battery - I don't want it, so I used a mono jack for input, then, after seeing that I had that problem, I switched to a stereo jack, omitting the connection to the battery.
Here is a picture I've taken.


@ bukas, here is a picture. Actually I checked all the wiring, all the components and everything is fine (above all because I can get the pedal to work while the in jack is outside the enclosure). I painted the enclosure with primer, then with acrylic spray can, and then with sinthetic transparent paint and a sealer.

That is all I can say guys!
Thank you,
M.

[Fender3D]

Is your DC jack insulated?

[Outtagetme]

Opps sorry here is the picture.

http://postimg.org/image/sez4925wr/

M.

[rousejeremy]

Is your DC jack insulated?

^This

[Outtagetme]

Is your DC jack insulated?

The seller says they are..so I guess they are!

M.

[Kipper4]

It really smacks of a ground problem.
Is anything on the circuit board touching the enclosure?
I noted that theres no Ic in the socket in the photo but i'm guessing you've had it in since you say it works outside of the box.
Use your meter to check the grounds. the jack plugs look like they might be preventing grounding with the plastic washers too.
It's got to be worth a look.

[rousejeremy]

Could you turn those jacks a bit so we can trace their wiring a little easier?

[rousejeremy]

Move the ground from ring to sleeve, or sleeve to ring and see if it changes anything.

[Govmnt_Lacky]

If the build works when the Input audio jack is removed from the enclosure and you plug in a cable and it DOES NOT work when you install the input jack into the enclosure and plug in the cable then it could only be 2 things:

1) When you install the jack, the TIP is somehow touching the enclosure when you insert the audio cable. Check for clearance
2) When you install the Input jack and tighten it down, the TIP contact on the jack is somehow getting shorted to the SLEEVE. Maybe due to overtightening or a faulty jack.

Recommend installing the Input jack into the enclosure, insert audio cable into Input jack, disconnect the other end from your guitar and read from TIP to SLEEVE on the guitar end of the cable. If it is directly shorted then you have one or both of the above problems.

Good Luck 

[Outtagetme]

Could you turn those jacks a bit so we can trace their wiring a little easier?

there you go!

http://img543.imageshack.us/img543/1238/foto2ebt.jpg

The black cable on the left side of the picture goes to the DC jack.

M.

[Outtagetme]

It really smacks of a ground problem.
Is anything on the circuit board touching the enclosure?
I noted that theres no Ic in the socket in the photo but i'm guessing you've had it in since you say it works outside of the box.
Use your meter to check the grounds. the jack plugs look like they might be preventing grounding with the plastic washers too.
It's got to be worth a look.

No, actually nothing is touching the enclosure - expect for wires..but that shouldn't be a problem, should it?
Yes no IC's because I hadn't install it yet - I installed it when I was done with all the soldering & stuff. I have never used a meter before..this might be a good chance to learn it. Can you tell me exactly where I have to place the tips?
Which plastic washers? They have a metallic nut on the outside, along with a metallic washer, then on the inside they have another metallic washer and then the body of the jack - maybe you're referring to the yellow parts of the jacks that you see in the picture - those are not directly connected to the enclosure.
Am i getting it right?

M.

[bukas]

does LED work when effect is enclosure ?
is the orange from 3pdt=signal out ? and is it connected to tip or sleve?

[Outtagetme]

does LED work when effect is enclosure ?
is the orange from 3pdt=signal out ? and is it connected to tip or sleve?

Yes the LED works all the time. The orage is the signal out, and it's connected to the tip of the output jack.

I checked the clearance and the tip is not touching the enclosure at all.

Don't know what to do next.

M.

[Kipper4]

What happens if you remove both in and output jacks from the enclosure  and then plug them in both ends (ie the jacks not touching the enclosure) does it work then?

This is a negative ground circuit isnt it?

[Outtagetme]

What happens if you remove both in and output jacks from the enclosure  and then plug them in both ends (ie the jacks not touching the enclosure) does it work then?

This is a negative ground circuit isnt it?

Yep, if I remove the jacks and let them hang free the pedal will work very fine.
I don't know what a negative ground circuit is - heard of it on the forum thread about debugging but that's it, I don't know more than that. I used the GGG's project, and the layout as well.
Now I measured between the input jack TIP and SLEEVE with the cable in, I get a reading of 0 V.

M.

[Govmnt_Lacky]

2) When you install the Input jack and tighten it down, the TIP contact on the jack is somehow getting shorted to the SLEEVE. Maybe due to overtightening or a faulty jack.

Try a different jack in the INPUT 

[Outtagetme]

2) When you install the Input jack and tighten it down, the TIP contact on the jack is somehow getting shorted to the SLEEVE. Maybe due to overtightening or a faulty jack.

Try a different jack in the INPUT 

I already tried two different jacks. I'm gonna try another one (maybe a different kind if I have one).
Now I took the jack off the enclosure, measured the ground and the signal tip on the jack, with the cable on the reading was 9 V, with the cable off is 0 V. Is that correct? Now it doesn't work even with the jack off :.

Thanks,
M.