Line 6 Flextone wah not wah-ing

[drewl]

Opened up the controller and by varying the output voltage with a resistor the wah sweeps.

Anyone know what the two optical LED's are or photocells or whatever they are?

Anyway to test them?

I have voltage to the cells as compared to the volume pedal next to the wah.
The plastic strip is good and tracks properly, just the voltage on the other side of the photocell is not changing.

Anyone ever order these?

[The Dude]

I've fixed a few of these by simply cleaning the photocell and pickup. Have you tried that? Sometimes they just get covered in dirt.

[drewl]

Tried cleaning the cells and the shade strip, no change.

Nobody has had to replace those?

How about a schematic for the controller?

I'll look for that and a BOM to try and find the part numbers.

Edit: okay, found the p/n#'s pretty easily
45-10-2056. And
45-10-4556

Now just gotta find a better source than Full Compass who want $3.55 each.

[Enzo]

If it is like many other optical systems, you have infrared LEDs shining on photo transistors. So on one side you should have typical LED voltage drops across the part. Do you? On the sensor side, try to exclude most of the room lighting, but measure voltage across the sensor, then block the IR beam with something opaque - a coin, a screwdriver blade, a piece of cardboard, something. Does the voltage change? The shaded strip blocks a varying amount of hte IR light, but typically if you can get all or nothing with a hunk of metal or other opaque item, then the strip probably works too.

So just like a reverb system, we need to decide if it is the send or the return that is faulty.

Full Compass identifies #4556 as an LED, so we are on the right track. And they call 2056 as a phototransistor, so I think I am fairly safe.

ANy chance there is a small number printed on the part?

[drewl]

Correct voltage across the infrared LED as compared to the one for the volume pedal next to the wah.
No change of voltage across the photoresistor when blocked or from the shade strip so that's probably the culprit.