need help madbeans cave dewller

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need help madbeans cave dewller

Postby stardemos » 08 Jan 2015, 21:01

hello.

i've built a cave dewller from madbeans using their etching layout, the pcb seems perfect but, i got no delay, just weak signal, i've made a few changes because i did not have the correct capacitors, changed the 1uf for a 1uf electolitic capacitor, and the 10uf tantalum for another electrolitic, everything else is ceramic capacitors and metal resistors.

with the probe i got signal in pins lpf1-in and out, lpf-2 in and out, but nothing more than this.
can someone help me please?
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Re: need help madbeans cave dewller

Postby karul » 08 Jan 2015, 22:41

Do you have 5V on pin1 - PT2399 ? Maybe your IC is dead?

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Re: need help madbeans cave dewller

Postby stardemos » 08 Jan 2015, 23:07

i'v 4.3v on pin 1
tried 2 ic's

pin voltages
1-4.3
2-2.1
3-gnd
4-gnd
5-1.98
6-2.10
7-3.92
8-3.93
9-1
10-4.26
11-0.08
12-2.14
13-3.92
14-0.4
15-0.4
16-3.9

5v at 78l05 out pin witch is geting a bit hot
i've noticed that the layout is wrong at this ic, so i've put it wright, i believe.
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Re: need help madbeans cave dewller

Postby karul » 09 Jan 2015, 00:25

Can you provide pictures of your PCB ?
What kind of a PS do you use ? Measure the voltage.
Do you have anther pedal with pt2399? If you do, use check the IC's if they are OK.

Suggestion: breadboard first, see if everything works fine, then solder.

General debugging guides:
http://www.sabrotone.com/?page_id=3484
http://www.geofex.com/fxdebug/fxdebug.htm
http://www.diystompboxes.com/pedals/debug.html

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Re: need help madbeans cave dewller

Postby stardemos » 09 Jan 2015, 09:31

the fotos:


the ps is a 9v regulated, i get 9.00v from it
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Re: need help madbeans cave dewller

Postby karul » 09 Jan 2015, 13:46

It looks like you have solder bridges.

Use continuity test from DMM to check for solder bridges, or enlarging lens for visual control.
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Re: need help madbeans cave dewller

Postby stardemos » 09 Jan 2015, 18:31

i thougt about it, then, i've desolder all components bent the edges to touch the board and resolder them, checked for bridges and none was detected by the multimeter...
still does not working..
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Re: need help madbeans cave dewller

Postby karul » 09 Jan 2015, 19:26

You don't have to desolder all the components if you are suspecting that you have solder bridges.

The quality of the picture you've posted is very poor.
However, check the regions inside the yellow squares. It doesn't look good from over here.
Also it looks like (I might be wrong - it's extremely hard to tell due to the quality of your picture) you are missing the copper traces inside those red squares. Check those too.

Also I suggest you to browse through this and other forums, to see what kind and quality of information (quality of pictures, data, etc,etc..) you need to provide, when you are asking for help. Respect other peoples time and effort.
Go through the links I gave you about debugging. Read them carefully.
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Re: need help madbeans cave dewller

Postby stardemos » 09 Jan 2015, 21:06

thanks for the help.

i'v stpotedand repaired what you have marked in red.

now i think i've made a very stupid mistake...
1st voltage regulator i've used, burned, so i check the datasheet and (didn't read the subtitle) inverted the position, so nou the power is suplied to the out pin... didn't understand how i got voltage in pin 1....

tomorow i'll do it right.
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Re: need help madbeans cave dewller

Postby stardemos » 12 Jan 2015, 18:34

i really appreciate your help, it wasn't only the 78l05, had a lot of cold solder,i've re-welded everything and now it works.
thank you all
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