Help me troubleshoot this pedal

Re: Help me troubleshoot this pedal

I marked up the diagram with the main power supply path



I also marked up the voltages as I understood what you were saying above. I was good with this bit...

cohara41 said:
Power supply is 20 V DC from the transformer. IC1 Pin 8 3V DC after TR1, Pin3 0V DC. IC2 Pin 7&8 3V DC. IC3 Pin2 0V DC, Pin 14 20V DC.
Click to expand...

...but lost the thread with this part, as I wasn't entirely clear which chip we were on

cohara41 said:
Pin 4 is 12V DC which is on IC1, 2 & 3. I'm counting 14 pins as it says on the pc board drawing. Hope these nunbers help. Cheers
Click to expand...

Let me know if I've interpreted it right, as if I have there are some unexpected readings appearing which could be due to an inaccurate diagram, a failed or modified circuit, or a measurement taken in a position different to that reported. If the diagram is correct though, any measurement taken to the right of TR1 on the green line should be identical.

Just one other query though, when the pedal is in the 'Off' position, are you still getting a clean signal through to your amp? Also, does the LED light up when the pedal is turned 'On'
 
Re: Help me troubleshoot this pedal

Chris, thanks for the markup. Pin#4 reading is the ground on IC1, 2 & 3, #4 being a ground with 12 volts DC from where? I know there's more than one IC1, 2 & 3 on the drawing & IC2 & 3 that you've marked power to have 12 volts on #4 but the IC1 you've marked doesn't have the pin#4 ground. The led lights up when the pedal is on & no signal passes on bypass . I took on off readings at each pin & will post them tonight. Thanks again for your time. Cheers
 
Re: Help me troubleshoot this pedal

OK. I'll redo it tomorrow evening (gone midnight here now). If you're getting 12v on those earth pins though, that suggests your earth return has been disrupted somewhere - is your input socket worn, as that's where it would normally go back to.
 
Help me troubleshoot this pedal

One thought, when you are testing the voltages, do you have a 1/4" jack in the input socket? Without that , voltages inside the pedal will float all over the place.
 
Re: Help me troubleshoot this pedal

Chris, the power input is exactly like a input/output to the pedal, guitar or amp. Thanks.
 
Re: Help me troubleshoot this pedal

Chris, the power input is exactly like a input/output to the pedal, guitar or amp. Thanks.
 
Re: Help me troubleshoot this pedal

Chris, that link you just posted just takes people to the Yahoo Mail login screen - think you must have copied the URL whilst you were logged into your own account. It would probably be easier to just copy the relevant pieces of information from that email directly into a post here - we don't need anything more than the explanation you were provided with.
 
Re: Help me troubleshoot this pedal

Chris, Thanks for lookin'. I've got a local that's helping me via email. I'll put the results up when we find the answer. I've made alot voltage readings, so many I can't keep'em all straight in my head. Have a great night...Cheers
 
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