DOD FX90 Works great...then effect fades after being on for a while. Help?

[pedalladep]

Hey, thanks for looking at my post. Some help would be appreciated, if possible.
When I click on my DOD FX90 delay it works great for a while. Sounds great, works as it should.
Then after about 15 minutes or so of use (time may be somewhat inaccurate), it begins
to lose it's effect. It still passes signal whether on or off and will produce a little bit of effect,
but the rich, full delay effect is almost gone and it doesn't do much.
The next day, it will do the same. Work great for a bit, then fade. 

  I don't think it's dirty pots or a bad input, etc . I've cleaned those.
The 'faded effect syndrome' is not intermittent, it happens every time,
so it's not like an iffy connection that comes and goes. I see mention of the trim pots needing
moved in some cases (or at least some suggest this with regard to some problems others have had).
It's possible that could the problem, but I don't think it makes sense
that it would be so consistent in 'working then failing' if it was just some oxidation in the trim pots.
I could be wrong. I was thinking a capacitor or transistor. What do you think?

    Thanks, and any info would be great. I have some soldering skills, though not much on 'boards',
but I'm willing to attempt a cap/transistor/resistor replacement or two if anyone's got some (meaningful, and specific )
instructions on that.

[MikeA]

I see you posted this same question on another forum a week or so ago and got some advice, did any of that help you?

[pedalladep]

I see you posted this same question on another forum a week or so ago and got some advice, did any of that help you?

I just replied to that post earlier this eve, asking him to clarify his comments. I'm not quite sure what he was saying.
He may be right on the money, but I didn't want to proceed somewhat 'blindly' just yet.
Looking for some more opinions ....possibly the same opinion. That post seemed to go dead....so I posted here.  Thanks.

[Rob Strand]

What do you think?

Measure the voltages when you first power it up and then after it goes kaput.
Good placed to measure are the opamps, transistors perhaps the compander IC's.
The voltage on the wiper of the bias trimpot would be useful.

Be careful probing you don't want to fry the delay chip, that would be bad.

Watch out for DOD schematics if you are following one, there's often many errors
and you need to make sure the board revision and schematic revision match.

My gut feeling is the bias trimpot is going open however the compander
wired as an expander could do some weird stuff as well.

[ElectricDruid]

Would this be the right schematic, do you reckon? It looks pretty close to me, and the board layout matches which is promising.

https://www.synthxl.com/wp-content/uploads/2020/04/DOD-FX-90-Schematic.pdf

[Rob Strand]

Would this be the right schematic, do you reckon? It looks pretty close to me, and the board layout matches which is promising.

https://www.synthxl.com/wp-content/uploads/2020/04/DOD-FX-90-Schematic.pdf

That trimpot at the bottom right could lose signal.  There's no DC voltages so you would have to use the DMM continuity checker.