Rebote 2 Delay - help

[KRK]

Hi everybody,

So I am troubleshooting my rebote 2 delay (board from tonepad.com) and getting a value of 9 v throughout the entire circuit. All IC pins measure 9 V. The only place I seem to read 5 v is on the input to the board and that jumps to 9 v the other side of the 1M resistor connected to the input.

I thought maybe the 5 V regulator was shot, so I replaced it, tested the old one that I had just removed and on a breadboard it was working like it should.

I checked and double checked for any shorts, especially along the 9 v in trace.

Double checked all components are correct except for a 470 K resistor instead of the 510k. The only thing is I have electrolytic caps for the .1uF caps. I set them up so that the negative is soldered to the ground trace. Could that cause a weird reaction like this?

Cheers!

[KRK]

Bump - This is the right bump. Any help for a first time build would be appreciated

Cheers!

[bluesdevil]

 If you only checked for shorts on the +9v rail by sight, it could be pretty easy to miss something. Use your meter in the continuity test "beep" mode and hopefully it will pick up something.
       You should get half voltage where the 12k resistor and 47uf cap connect together... what is the reading at that junction?
     

[Fp-www.Tonepad.com]

Most of the times it's a bad wiring or soldering issue (bridge or cold joint somewhere) so inspect all the joints with a magnifying glass.

It's also a good idea to use sockets for the IC's and power the circuit without the ICs in to take measurements before putting them in, this can save the ic's.

[KRK]

If you only checked for shorts on the +9v rail by sight, it could be pretty easy to miss something. Use your meter in the continuity test "beep" mode and hopefully it will pick up something.
       You should get half voltage where the 12k resistor and 47uf cap connect together... what is the reading at that junction?
     

I'm checking for continuity, when you say 12k and 47uF do you mean the 10k that is connected directly to the live 9v trace and the 47uF just below it? I'm not being funny but there is only a 1 uF right by the 12k resistor right before the output wire.

Thanks for helping, it is really appreciated.

[KRK]

Most of the times it's a bad wiring or soldering issue (bridge or cold joint somewhere) so inspect all the joints with a magnifying glass.

It's also a good idea to use sockets for the IC's and power the circuit without the ICs in to take measurements before putting them in, this can save the ic's.

Thanks for the magnifying glass tip. That will help to see where I went wrong.

[bluesdevil]

Ooops, I was looking at version 2.5!! Yes, the 1/2 voltage rail should be  where the 10k and 47uf meet. Also try measuring after the 4.7k that connects to the third pin of IC  2.
      Besides checking for shorts with a continuity meter test, I like to scrape between tight traces with a utility blade or dental pick just in case. Good luck!!!!!

[KRK]

Bluesdevil, thanks so much for the help! I'm at least reading the correct voltage on the circuit... Now to get it to delay instead of bypass regardless of the switch position...Got to check a few things and see if I can't solve it... Or get a new PT2399 because of the frying possibility I'll get this puppy working - The voice of determination!

[bluesdevil]

You're welcome, glad it's coming together. Try simplifying the wiring by omitting the bypass switch for now and just connect the circuit's ins/outs to jacks to see if that gets anywhere. Could just be an offboard wiring mistake or bad switch now.
    Yeah, you gotta be determined.... nothing worthwhile comes easy!!

[KRK]

You're welcome, glad it's coming together. Try simplifying the wiring by omitting the bypass switch for now and just connect the circuit's ins/outs to jacks to see if that gets anywhere. Could just be an offboard wiring mistake or bad switch now.
    Yeah, you gotta be determined.... nothing worthwhile comes easy!!

That's my thinking. For a first project I am glad it hasn't worked out easily, now I know what to expect from future projects... Obviously I'm not put off, and have a bunch of new troubleshooting knowledge in my utility belt 

I had the same idea to wire it directly and eliminate the switch and bypass wiring as the culprit.

Thanks again for the help!