Renometer input issue

[snk]

Hello,
I'm a new member, also quite a newbie as far as it comes to DIY. I hope I am asking this question in the right section (if not, feel free to move it in the right place) ?

I am just got a Renometer which seems awesome but is faulty.
When I power it on, no sound is coming out.
If i put all the faders way up, and the boost on, it increase the noise and so I can hear the filter action, but the input signal is still very very low (but a little bit audible).
From my (very little) understanding, the"processing" section (faders, inductors) and the output section is working fine, but something close to the input (start of the signal path) is faulty.
Could it be a faulty opamp (I see it at the beginning of the signal patch), or electrolytic capacitors getting old (they look ok, but they must be very old) ?
Thank you in advance

[PRR]

Welcome.

Examine the input jack. Jacks get a lot of abuse so that is a very good bet.

Replace C1. Does that help?

Then see the Debugging Page and post the op-amp voltages.

[snk]

Hi, thank you for the help (and the welcome message).

The jack plug seems ok.

New Nichicon electrolytics are on their way. I have inspected the circuit more closely : i will first replace the electrolytics capacitors close to the input and opamp, then the one near the output, and maybe also the ones next to the faders.
There are also 3 ceramic capacitors (and 3 polyester) : do they tend to get faulty while getting old as often as the electrolytics ones ?

If changing the capacitors do nothing, I will take measurements of the op-amp voltages.

[snk]

Hi,
So,  i changed the electrolytics capacitors and the Renometer now works how it should
Thank you  for your help, PRR.

[snk]

Hi,
I was wrong : the issue is still here (but different).
In fact, the Renometer works fine for some seconds, and then the sound is messed up (a bit like distorsion, or like a dying battery).
it looks like some component is working for a little while, and then not any more, but i don't have any idea which could cause the issue... ?

[thermionix]

Usually connections go intermittant more often than components do.  Cracked solder joints, stressed wires, etc.  I'm not familiar with this pedal, but if it has a DC jack it's most likely one with an internal switch (to cut off the battery).  If that gets oxidized it can act like a resistor and lower your operating voltages (dying battery sound).  Easy to check for a DC drop.

[snk]

Thank you for your reply.
Still, there is something i don't understand, which makes me think it is not a cold solder or a faulty jack : the scenario is always the same : it always works when i start the pedal, and doesn't works after maybe 20 seconds. It not as if sometimes it works and sometimes not : it always work when i engage the pedal on (which at first made me think the issue was fixed), at the beginning of a session.

And, as i am not a guitarist (but a keyboardist with the pedal patched to a patchbay), i am neither dancing around on stage or engaging it by stomping with my foot. I am in a peaceful, quiet studio when the pedal starts to distort after a little while, with the in & out jack patched into a patchbay so the cables don't move.

[thermionix]

Hmm, I don't know.  You've already replaced the electros.  Does it always work fine right after startup, or do you have to leave it off for a while?  I see it has two batteries for a bipolar supply.  Are you using batteries or an adapter?  If batteries, what type?

[PRR]

....the scenario is always the same : it always works when i start the pedal, and doesn't works after maybe 20 seconds.

Then see the Debugging Page and post the op-amp voltages.

[snk]

Hello
Thank you for the suggestions and help.

Then see the Debugging Page and post the op-amp voltages.

It seems that your link points out to this thread ?

Does it always work fine right after startup, or do you have to leave it off for a while?  I see it has two batteries for a bipolar supply.  Are you using batteries or an adapter?  If batteries, what type?

I have to leave it off for a while : if i power it off for some seconds or a minute, the issue is here again right after powering it on again.
I'm using batteries. They are regular alkaline 9V batteries.

I checked, and I made a little recording. In fact, it's mostly sound drop-outs (volume loss), not much crackles or distortion.
FIrst, a "dry" synth loop is playing. Then, i start the Renometer, tweak each frequency band, and quickly the sound drops out. Then, i switch it off, and then on again : the issue is still here.
https://vocaroo.com/i/s0gI5qaRgHqi
https://clyp.it/hytr4p5q

[bluebunny]

Paul meant here: Debugging thread.  It really works.

[snk]

Ok, i get it

[snk]

Hi.
This week-end, i opened it, and checked the jack sockets : they were indeed in very bad condition, way worse than expected (the output jack literrally split i my hand, the other one was covered with dirt). I changed them, remade most of the wiring, and, as i suspected some intermittent switching from the batteries, i made a little power supply for it.
Unfortunately, it didn't change the strange behaviour, and i think that the issue is a bit beyond me for the case (well, i spent too much time on it, i feel like i need to move on).
I might come back to it in a couple weeks/months, or i will send it to a friend who is more skilled than me.
Thank you all for the help, and i will let you know what was the issue when it will be done