Looking for help with PT2399 delay - signal passing with no delay effect

[apguitardude]

Hi there, I am new to this site as a poster and havent had much luck browsing for answers so I thought i would ask the message board.    I have breadboarded a Rebote 2 delay pedal and was successful, however, while switching the delay time potentiometer the echo effect stopped.  I am still getting a "dry" signal but no echo effect whatsoever.  I decided to rebuild from scratch... 3 times and getting the exact same result of dry signal with no effect.   After some browsing I found a "fix" in which pins 3 and 4 are connected together and grounded - this did not fix the issue.
  I checked my regulator and pin 1 of the IC and voltages are correct.  Did the beep test on my connections and even tested my jumper wires and external components for issues but everything seems fine.
 
  I am self taught in electronics but have built many fuzz, booster and distortion pedals and having trouble stepping into the modulation-type effects with this chip this in particular.

  I will attach the schematic here if anyone has any experience with  this or suggestions.

Thanks in advance for any and all suggestions!

[Slowpoke101]

Welcome to the forum.

This may seem insane but remove the PT2399 from your board and short out all the pins at the same time. Sometimes a PT2399 can latch-up when the delay-time pin supplies too much current, such as when changing the pot or shorting something out. The latch-up condition remains even after powering down and can remain for quite some time. Shorting all the pins can usually restore a latched chip. Try it.

[apguitardude]

thank you I will try this.  Is it possible for this to have happened to 3 different IC chips?   As I said, I have built the exact circuit now 4 times and only getting clean signal and that's after swapping for 3 different chips so I'm completely stumped.   I know the schematic works because on the 1st attempt all was well until the "lock up".
 

[Kipper4]

Another Jim came up with a pearl.
Use tin foil to short the legs. Push the legs through together.

Pin6 needs to see a min resistance. Can't remember off the top of my head but think it might be 1k minimum.

If you look at some of the PT2399 delay designs. Some have a built in anti latch up transistor arrangement.


http://www.valvewizard.co.uk/jennygreenteeth.html

http://www.valvewizard.co.uk/PT2399_Data_Notes.pdf