REBOTE 2.5 troubles

[roofer1]

hi, new here to the forum.  i have read all the usual troubleshooting stuff, so dont blast me for wasting your time please!  Rebote 2.5, using tonepad's pcb, and his offboard wiring example 5 (using a 3pdt, led, dc jack and battery).  it was working great at one point, but now only on bypass.  it appears that the board is getting power, but the signal is not getting through the board when it is on.  i have checked the resistors, caps etc, but i dont know how to test the ic (pt2399) to see if it is fried or something.  i used ic sockets of course, and like i said it was working great up until about a week ago.
i am new to the multimeter thing, so i dont know how to or what to test other than continuity and making sure that 9v is getting to the board.
thanks for the help!  i know i can fix this if i can figure out what is wrong with it!

[Kornell]

Try the advices of the  debugging page: http://www.diystompboxes.com/wiki/index.php?title=Debugging

[roofer1]

yeah, i have found the debugging page helpful in the past with other projects, but i just cant seem to get this REBOTE to come through for me.  i really dont understand enough about ic stuff to test them, does that make sense?  i have repeatedly checked the obvious stuff and cant find anything...
is it possible for an ic to die just through the normal building/debugging process?

[scaesic]

use an audio probe, on page posted, go through the pcb from signal in and trace it all the way through to out, you should come to a point where you find there is no sound, then check the components/soldering around that point.

[Auke Haarsma]

If it worked and stopped working now, than you can be pretty sure somewhere a connection is broken. The aforementioned audioprobe will allow you to follow the guitarsignal (and teach you alot about what the circuit does!) and pick the spot where the signal is lost. Check solderjuntions around that spot.

If you stay in trouble, please post the information as listed in the "Debugging, what to do when it doesn't work"-thread (sticky at this board). This will help others to check the voltages and see where the error most likely will hide.

It's a great pedal, I love the sound of it!

[roofer1]

yeah that makes sense about the audioprobe.  is it really as easy to do as described on that page?  as far as the sound of the rebote goes, i have one that i built (this broken one is a friend of mine's) that i love, i actually ended up selling it to a drummer sunday that heard it for a few minutes and promptly pulled his wallet out!
i appreciate the responses...
  want to post all those so that you guys "in the know" will have more info to look at.  how do i measure the voltages at the ic pins?

[Auke Haarsma]

how do i measure the voltages at the ic pins?

Get your DMM, put one probe to ground and put the other to the pins. Now you see the voltage on the pin.

[scaesic]

how do i measure the voltages at the ic pins?

Get your DMM, put one probe to ground and put the other to the pins. Now you see the voltage on the pin.

more specifically, so you dont get wrong polarity...

attach the black dmm probe to "com" or "ground", attach the red one to "V" for voltage. now hold the black one on a "ground" trace, or ground at the supply, or input/output jack sleave, then when you hold the red probe against each pin on the ic you will see a votlage reading.

just for reference ic pins are labelled in this convention: 

1----8
2----7
3----6
4----5

from a top down view.

[roofer1]

thanks man, i have shelved the rebote for a few days whilst working on other stuff, but this afternoon i am going to measure those voltages and let you guys know, hopefully we will get some results!

[roofer1]

okay, in the rebote 2.5 layout and schematic http://tonepad.com/getFile.asp?id=98 the IC1 does not seem to be getting any measurable voltage at any pin.

[Auke Haarsma]

In that case there could be two causes:
1- You are not using the DMM correctly. -> If you get voltages at other points, this is not the case.
2- There are some bad traces, cold solder joints on route to the IC. Try to follow the Voltage from the entry point (+9V) until you find where the voltage stops. Check all components around that place and resolder if necessary.

(btw: is it just me or is the tonepad site down? www.tonepad.com gives me a commercial-site...)

[scaesic]

hello, there could be another reason for not reading any voltage.

if you did the trick where you need to put a jack in the input/output in order for the pedal to be "on".

i've done this a few times, wondered "why the hell amnt i getting any voltage?", only to realise i didint have a jack in the input.