Build Your Own Clone Message Board

We have a Version 2.0 of the Silver Pony that does the following

The things that work/that are functional on the pedal:
- Bypass signal works when pedal is switched off
- Bypass signal works when pedal is switched on
- LED lights up w/  9 volt adapter plugged in and/or 9 volt battery
- Volume knob will raise and lower the volume accordingly when the pedal is switched on

Things that do NOT work on the pedal:
- When the pedal is switched on the Gain knob or Tone knob are turned, there is no effect to the sound = no overdrive/distortion etc
- When the switched are switched, this has no effect on the sound

Steps that have been taken so far:
- ALL solder joints have been reflowed, including joint under the Gain Pot as well as all IC sockets
- IC socket joints were reflowed WITH the IC removed
- Performed continuity check up to test point just above TL072 IC in lower right hand corner
- Captured voltage measurements on IC pins (see below)

The following voltages were measured with a DMM  with DC measurement on the following IC pins:
IC - 76605
1:  6.69 volts
2:  8.00
3:  .194
4:  .193
5:  7.99
6:  6.68
7: 1.226
8: .194

IC TL072 Left (towards center of board)
1: 1.309 volts
2:  1.308
3:  .984
4:  0 (zero volts)
5:  8.86
6:  8.12
7: .656
8: .1011

IC TL072 Left (lower right corner of board)
1:  8.84 volts
2:  .122
3:  0 (zero volts
4:  .883
5:  8.83
6:  .910
7: .197
8: .193

Any thoughts on what troubleshooting should be performed next?Given the low voltages at the IC pins and zero DC voltage on 2 of the pins, is there a possible resistor that is out of place OR are the ICs 'cooked/ broken/ faulty'?

https://www.dropbox.com/s/z2ruk4axl1b9j ... 0.jpg?dl=0
https://www.dropbox.com/s/tamiynuqdsfsc ... 1.jpg?dl=0
https://www.dropbox.com/s/lqzwg0uiwvvir ... 2.jpg?dl=0
https://www.dropbox.com/s/6moxdv4j4g6ku ... 3.jpg?dl=0
https://www.dropbox.com/s/980r0cdbor8yc ... 4.jpg?dl=0
https://www.dropbox.com/s/gtt3qi4uzmjv4 ... 5.jpg?dl=0
https://www.dropbox.com/s/iymighyzzilgo ... 6.jpg?dl=0
https://www.dropbox.com/s/sexdr638mm7d1 ... 7.jpg?dl=0

Your voltages are way off, but I'm not entirely sure you are labelling your pins correctly. Pins 1 and 8 of the 7660 are connected, so they should have the exact same voltage. Please take voltage again.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Keith- Thank you for spotting the error in my pin identification- I corrected the pin orders and captured the following values on the correct pins.

For a next step should I re-check that the resistors values match the layout?
Also when I measured the voltages I used a 9 volt battery for the power source.

The following voltages were measured with a DMM with DC measurement on the following IC pins:
IC - 76605
1: 6.69 volts
2: 8.00
3: .195
4: .193
5: .194
6: 1.226
7: 6.83
8: 7.99

IC TL072 Left (towards center of board)
1: 1.309 volts
2: 1.308
3: .984
4: 0 (zero volts)
5: 1.011
6: .656
7: 8.12
8: 8.86

IC TL072 Left (lower right corner of board)
1: 8.84 volts
2: .122
3: 0 (zero volts
4: .883
5: .193
6: .197
7: .910
8: 8.83

Those voltages are still way off, but they at least make more sense now. You appear to have a problem with your bias voltage. Also, your charge pump isn't producing double voltage. Please post pics of your build and also take voltage again, but this time with all the ICs out of their sockets.

My name is Keith, not Kevin, BTW.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

You have the position of the 7660S charge pump switched with one of the TL072 op amps. Swap them and see where you're at. See image below for correct locations:

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Keith-

Forgive the gaffe w/ your name, I realized that I mistyped it and made the edit to to my post right after I caught it.

duhvoodooman -

I feel a bit foolish about having the ICs in the wrong spot. Thank you for catching that . Now that the ICs are in correct places the pedal now makes new sounds:
- Turning up the volume knob produces a 'motorboat' sound
- The gain knob when turned up, will start to 'shriek' at about 9 o'clock
- The tone knob raises and lowers the frequency of the shriek from a low rumble to a high pitched squeal

With that, these are the voltages w. the ICs removed:
7660S
pin
1: 4.383
2 : 4.386
3: 4.557
4: started at - 0.016 went to -0.001
5: 4.556
6: 4.56
7: 4.387
8: 8.54

top center IC TL072
1: 4.55
2: 4.56
3: 4.18
4: 0 (zero volts)
5: 4.54
6: .4.552
7: 4.386
8: 9.13

lower left IC TL072
1: 9.13
2: 2.7
3: 0 (zero volts)
4: 2.23
5: -.027
6: 0 (zero volts)
7: 0 (zero volts)
8: 9.13

These are links to my picture of the board/build. Let me know if you can see these in Dropbox- The ICs have been switched to the correct locations as these photos were taken before the swap:
https://www.dropbox.com/s/z2ruk4axl1b9j ... 0.jpg?dl=0
https://www.dropbox.com/s/tamiynuqdsfsc ... 1.jpg?dl=0
https://www.dropbox.com/s/lqzwg0uiwvvir ... 2.jpg?dl=0
https://www.dropbox.com/s/6moxdv4j4g6ku ... 3.jpg?dl=0
https://www.dropbox.com/s/980r0cdbor8yc ... 4.jpg?dl=0
https://www.dropbox.com/s/gtt3qi4uzmjv4 ... 5.jpg?dl=0
https://www.dropbox.com/s/iymighyzzilgo ... 6.jpg?dl=0
https://www.dropbox.com/s/sexdr638mm7d1 ... 7.jpg?dl=0


Thank you both!
JP

No, worries. Happens all the time. Sorry I missed your dropbox links in the first post.

I am reluctant to put much stock in your voltage readings because there are several places where the voltages should all be exactly the same, where yours are not. And then several places that should be ground and no connection at all (0V), but you are saying there is a voltage present.

You've got some areas of concern. Image 4974 and 4975 show some sloppy soldering that could be causing multiple shorts which could cause the odd voltage your seeing. Please clean those areas up. Use the continuity test on your meter to make sure there are no more shorts, and retake voltages.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

For comparison sake, below are the IC voltages from my fully functional SP Rev.2.1. Note the negative DC voltages on pin 4 of the upper TL072 and pins 4 & 5 of the charge pump. These MUST be present if the charge pump is working correctly.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Keith and duhvoodooman-

Thank you for the guidance on what to do next, I really appreciate it. I'll give it a try and let you know how it goes.

Thank you-

JP