Fixing an RV-5?

[sirlemonhead]

OK,

This is probably hopeless, but I bought a really cheap RV-5 for parts on ebay a while back. Like the OC-2 I fixed recently, I figured I'd see if I could get it working.

The symptoms are no power LED lights on battery or PSA adapter. No audio signal goes through with the pedal "on or off". I don't know the history of the pedal, but I guess the CPU or DSP or something is fried?

I don't see any burned or damaged components on the board and I'm measuring 3.3v in a few different places.

Is the switching not the typical FET thing and instead handled by the CPU?

Here's the schematic if anyone thinks they can help - https://www.dropbox.com/s/2df1z0ob08ady ... ematic.pdf

laurie?

I see 3.3v at C77 which is at the output of the DC/DC section.
I'm also getting 3.3v at R73 which is on the switch line and connects to the CPU.

Is there anything I should check next or is this just a waste of time?

[laurie]

Ahhhh... it is a LOT more complicated than an OC-2. BUT the thing in your favour is that it has a complete failure so it might be something simple.

I'll have a look at it tomorrow.

[sirlemonhead]

Thanks! No rush either, it's been sat here for a while so it can wait!

[laurie]

Do you have access to an oscilloscope?

[sirlemonhead]

Unfortunately not. I assume something like this would be too low resolution? https://www.amazon.co.uk/KKmoon-Handhel ... op?ie=UTF8

[laurie]

That kit looks interesting... It *should* do the job.

The RV-5 has a "test mode". Take out the battery, make sure to have a PSA (or equivalent) power supply available, turn all the knobs fully counter-clockwise. Hold down the treadle and plug the PSA supply into the pedal while holding down the treadle. Does the LED come on? If the LED comes on, release the treadle... what happens?

[Pepe]

Oh, what is supposed to happen with the "test mode"?

[laurie]

Many things... let's see if it works at all first.

[chromandre]

Oh!!! I thought I had a dead RV-5 but it makes a bit of digital noises in “test mode”... can it be formatted or something? I can’t find the service manual anywhere

[sirlemonhead]

Hi,

The LED lights dimly for an instant when I connect the power adapter. Releasing the treadle does nothing.

Same thing happens if I have an input jack in or not, and also if I hold down the treadle or not - brief dim LED flash then nothing.

I don't hear any noise with an output connected when doing any of this other than a thump noise when connecting the power - like what you'd get when connecting an input jack to an amp etc