Pro-Ten/Blue _Blinking LED

[Kaiwa]

Hi,
Does anybody know what could cause this problem:
When the pedal is active the led is blinking (on/off in a regular tempo). When volume and tone are turned on max the 'blink' can be heard through the amplifier. The sound of the guitar does not come through.

Any ideas?

 

[PJS]

My bad, I was looking at the pro-ten green docs. Oops. Sorry. Fig is right though - the should be the other way around

 

[Kaiwa]

Oh what a shame

The pedal works, somehow...
The volume knob works, but there's just on or off.
The same for tone, there's an a'area' from 9-12ish where it is quite bright, the rest is muddy and dark.

 

[music6000]

Oh what a shame

The pedal works, somehow...
The volume knob works, but there's just on or off.
The same for tone, there's an a'area' from 9-12ish where it is quite bright, the rest is muddy and dark.

When you replaced the Op Amps, You swapped the order?????
Check your Op Amps!
fig has pointed this out above!
This is what it should be :

 

[Kaiwa]

When you replaced the Op Amps, You swapped the order?????
Check your Op Amps!
fig has pointed this out above!
This is what it should be :
View attachment 19326

Yes exactly!

I changed the order the way you show and have now those weird problems with the volume an treble pots as described. Drive works fine.

Any idea what could cause a volume knob behave like this: there’s either no volume, or volume but no increasing of the signal while turning the knob?

 

[giovanni]

Uhm the volume knob issue may be caused by a short somewhere or maybe the pot is busted. Hard to say. I don’t have time to look at the schematic right now, but it you know how to read it, I would check continuity to start, then move on to an audio probe.

 

[fig]

Fig is right though

Again? That makes.........okay once!

The Vcc is on pin 8 of the TL072 and pin 7 of the TL071. When you applied power to them while incorrectly socketed, it may have damaged one or both chips. With a makeshift audio probe (a piece of wire with one end connected to the pedal's OUT tip) you can check the IN+ and OUT+ pins of both chips with the pedal engaged and at least determine if signal is being passed and/or amplified.

That said, these other folks are much more knowledgable than I, so please take my thoughts with a jigger of salt.

 

[Kaiwa]

I replaced both chips when changing to correct position to be sure. I kept them, that's a good exercise to test them. I'll try tonight.

Concerning the pots, I think I have to research how to test them, never done this before.

 

[ADAOCE]

I made the same mistake using two TL072s! Tripped me up til I looked at the doc