Ibanez Echo Machine (Dead End FX Inchindown) not working

[captaincoconut]

Fellas, I'm new here and currently working on an Ibanez Echo Machine EM5 build. I use the Inchindown PCB by Dead End FX. Unfortunately I can't get it to work - all I get is a clean sound (in both bypass states) with no echo happening. As this is my first delay build I'm not quite sure where to start looking for a problem, so I'll start with giving y'all some voltage readings from the ICs and transistors. Hopefully someone can push me in the right direction.

I checked the wiring and polarity countless times. Looks OK to me. I also redid all solder joints. Changed nothing. Fiddling with the trimmers didn't help either. Help?

Link to the schematic is here.

1. Supply voltage: 9.20V

2. 5V regulator (the project calls for a LM78L05, but I use a L7805CV here) is putting out a stable 4.96V.

3. IC1 (JRC4558D):
- Pin 1: 4.58V
- Pin 2: 4.58V
- Pin 3: 4.58V
- Pin 4: 0V
- Pin 5: 4.40V
- Pin 6: 4.60V
- Pin 7: 4.60V
- Pin 8: 9.20V

4. IC2 (JRC4558D):
- Pin 1: 4.58V
- Pin 2: 4.58V
- Pin 3: 4.58V
- Pin 4: 0V
- Pin 5: 4.58V
- Pin 6: 4.58V
- Pin 7: 4.58V
- Pin 8: 9.20V

5. IC3 (SN74HCU04N):
- Pin 1: 0V
- Pin 2: 4.96V
- Pin 3: 0V
- Pin 4: 4.96V
- Pin 5: 0V
- Pin 6: 4.96V
- Pin 7: 0V
- Pin 8: 0.55V
- Pin 9: 4.36V
- Pin 10: 4.34V
- Pin 11: 0.83V
- Pin 12: 0.83V
- Pin 13: 2.60V
- Pin 14: 4.96V

6. IC4 (M65831AP)
- Pin 1: 4.96V
- Pin 2: 4.30V
- Pin 3: 0.37V
- Pin 4: 4.96V
- Pin 5: 4.96V
- Pin 6: 4.96V
- Pin 7: 4.96V
- Pin 8: 0V
- Pin 9: 4.96V
- Pin 10: 0V
- Pin 11: 0V
- Pin 12: 0V
- Pin 13: 2.51V
- Pin 14: 2.51V
- Pin 15: 2.51V
- Pin 16: 2.51V
- Pin 17: 0V
- Pin 18: 0.91V
- Pin 19: 2.48V
- Pin 20: 2.51V
- Pin 21: 2.51V
- Pin 22: 2.51V
- Pin 23: 2.51V
- Pin 24: 4.96V

7. Q1 (2SA1015L)
B: 4.59V
C: 2.60V
E: 4.93V

8. Q2 (2SC1815)
B: 0.58V
C: 2.40V
E: 0V

9. Q3 (2SC1815)
B: 0.54V
C: 0.54V
E: 0V

10. Q4 (BS170)
D: 0V
G: 2.35V
S: 0V

11. Q5 (2N3904)
E: 2.13V
B: 0V
C: 2.13V

Pictures from both sides of the board (some parts are soldered on the other side of the pcb to make place for top mount jacks):




Any kind of help appreciated!

[anotherjim]

Looks like your delay chip isn't being clocked. Haven't worked on those but I'd start by expecting to see around 2.5v on IC4 pin 2. Really it should be a square wave there and 2.5v is the average voltage a DMM will read the square wave as.

Give the circuits around the speed control & IC3 a good look. I don't understand that clock oscillator myself but IC3 pin13 & 12 voltages don't look right. Where does IC3 pin8 go to?

[iainpunk]

i don't know how delay chips work, but that oscillator doesn't have a 50% duty cycle, its more than a 95% duty cycle, so a higher voltage isn't odd to find. (its a simple relaxation oscillator).

cheers, Iain

[anotherjim]

OK, it might not care about clock duty cycle. Probably sequenced internally by edge-triggered counters.

Looks like audio probe required.
Input audio should be found at...
IC1 pins 7 & 1.
IC4 pin 22.
Echo audio at...
IC4 pin15
IC2 pin7
Input mixed with echo at...
IC2 pin1

[captaincoconut]

Looks like your delay chip isn't being clocked. Haven't worked on those but I'd start by expecting to see around 2.5v on IC4 pin 2. Really it should be a square wave there and 2.5v is the average voltage a DMM will read the square wave as.

Give the circuits around the speed control & IC3 a good look. I don't understand that clock oscillator myself but IC3 pin13 & 12 voltages don't look right. Where does IC3 pin8 go to?

i don't know how delay chips work, but that oscillator doesn't have a 50% duty cycle, its more than a 95% duty cycle, so a higher voltage isn't odd to find. (its a simple relaxation oscillator).

cheers, Iain

OK, it might not care about clock duty cycle. Probably sequenced internally by edge-triggered counters.

Looks like audio probe required.
Input audio should be found at...
IC1 pins 7 & 1.
IC4 pin 22.
Echo audio at...
IC4 pin15
IC2 pin7
Input mixed with echo at...
IC2 pin1

Thanks guys, that's a starting point! I'm going to audio probe the circuit once I get back to it and get back with my results ASAP. 

[PMowdes]

I'd also check that your delay IC is legit, I had some duds from Banzai in Germany.

[captaincoconut]

I'd also check that your delay IC is legit, I had some duds from Banzai in Germany.

Oh boy, that's were I got mine...I ordered two from them, none of them work. Know about any reliable source, preferably in Europe?

[PMowdes]

I think we got ours from here for the validation build

https://www.ebay.com/itm/371086009397

[captaincoconut]

OK, it might not care about clock duty cycle. Probably sequenced internally by edge-triggered counters.

Looks like audio probe required.
Input audio should be found at...
IC1 pins 7 & 1.
IC4 pin 22.
Echo audio at...
IC4 pin15
IC2 pin7
Input mixed with echo at...
IC2 pin1

I probed my build this morning and here's what I got:

Dry
IC1
Pin 1 - Yes
Pin 7 - Yes

IC4
Pin 22 - Yes

Echo
IC2
Pin 7 - No

IC4
Pin 15 - No

Dry/Echo-Mixed
IC2
Pin 1 - Dry only

Not sure how to proceed from here 

I think we got ours from here for the validation build

https://www.ebay.com/itm/371086009397

Thanks, I'll look into it!

[captaincoconut]

Update: I ordered some new delay ICs from the seller in China. They arrived after only 2 weeks aaaaaaand....it works  Things can be so easy sometimes, thanks for the help guys! I'm posting some pictures once I've finished the enclosure