Lectric-fx flintlock flanger is killing me.

A

_aj666

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I purchased 2 PCBs. Same issue. Everything measured and installed correctly on the second build, especially after the fail on the first one. I have no idea what to do from here. I've tested all my LT1054 chips upon socketing them and both come back with the same reading. I don't get 15v at the test pad, only getting 6.95. everything is clean. I just don't get it 😭
 

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Try removing all your ICs (besides the LT1054) first so you can check an "unloaded" voltage from the charge pump. Then you can insert the ICs one at a time (remove power before inserting) and see which one is pulling the rail down. My guess is that there's a problem somewhere else that's trying to pull more current than the LT1054 charge pump can supply, and that's dragging the voltage down.
 
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vigilante398 said:
Try removing all your ICs (besides the LT1054) first so you can check an "unloaded" voltage from the charge pump. Then you can insert the ICs one at a time (remove power before inserting) and see which one is pulling the rail down. My guess is that there's a problem somewhere else that's trying to pull more current than the LT1054 charge pump can supply, and that's dragging the voltage down.
Click to expand...
Thank you, going to give this a go right now. I really hope this will lead me to the issue.
 
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Just tested this out, getting nothing at the 15v and ground pads after removing all ICs. But when I test each leg at the ground and LT1054 I get the current readings.

1. 2.29
2. 5.24
3. 0.00
4. 0.00
5. 0.00
6. 2.55
7. 1.43
8. 9.42
 
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Where did you get the LT1054? Did you leave the 7815L in (and is it oriented correctly)? Are D8, D9, and D13 installed correctly and not shorting?

Your pin 6 Vref voltage looks good. Pins 3 and 5 are both firmly seated at GND?

EDIT: You could also try removing C37. That would give you the typical doubler circuit with the OSC pin left floating.
 
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benny_profane said:
Where did you get the LT1054? Did you leave the 7815L in (and is it oriented correctly)? Are D8, D9, and D13 installed correctly and not shorting?

Your pin 6 Vref voltage looks good. Pins 3 and 5 are both firmly seated at GND?
Click to expand...
Purchased the LT1054 from stompboxparts, and the 7815L was taken out while testing. As far as I know all diodes are installed correctly according to the build doc, and from what I've seen they're installed the same as everyone else's builds.

Can you explain this further? 😅

"Your pin 6 Vref voltage looks good. Pins 3 and 5 are both firmly seated at GND?"
 
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_aj666 said:
Your pin 6 Vref voltage looks good. Pins 3 and 5 are both firmly seated at GND?
Click to expand...
The pin 6 reading you reported is where it should be. You listed 0 V for both pins 3 and 5, but I wanted to make sure that they are well seated in the socket as the pin 5 voltage must be kept at or below the pin 3 voltage or the device will go into shutdown.
 
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benny_profane said:
The pin 6 reading you reported is where it should be. You listed 0 V for both pins 3 and 5, but I wanted to make sure that they are well seated in the socket as the pin 5 voltage must be kept at or below the pin 3 voltage or the device will go into shutdown.
Click to expand...
Right on, I can check this and make sure it's seated properly. But from what I noticed, it was in there good. Should I re test this with the 7815Linstalled as well?
 
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That’ll make it easier for you since you would be able to test the 15 V pad. You can test the pad for the input pin of the regulator for something above 15 V if you want to keep it omitted though.
 
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Is R61 a 270R or a 27R? Looks like the latter, although its tough with photos to get the colors right. Anyway if 27R it may current load the voltage supply, thus pulling down the voltage.

Probably good to verify R44, R51 and R61. When I have voltage supply issues, I check the resistors to ground in the supply section.
 
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benny_profane said:
I admittedly didn’t even look to see if that was the case. Glad it’s sorted. Good luck calibrating!
Click to expand...
Yeah I ended up getting a reply back from Keefe, and he mentioned that if they were in the wrong way I might be getting wonky readings which was the case. Luckily I socketed everything. Hopefully calibration isn't to crazy. I've been going over the moosropotomus method, seems pretty straight forward. Just tedious.
 
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