Curious about Whammy control circuitry.

[jrc4558]

Hi all!
I have received a pedal for repair, its a whammy pitch bender. It sounds fine, but the control pedal acts strangely too fast. The whole sweep occurs in about 15% of the whole travel of the pedal. Inside I found a red LED and a funny looking clear rectangular component, which obviously is a photosensor of some sort, but I dont exactly know. Between them there's a strip of plastic, with varying opacity, which is moved by the pedal. The pitch changes depending on the degree of illumination of the photosensor thing.
I have two questions:
1) Anyone has a schematic of a whammy? I'm curious to see the parts...
2) What could cause such a behaviour of the control range?
So far I found no problems with voltages ( I measured voltage regulators) and all other components where I can see a power line. No shorts to ground in the PSU either. The rest is a mystery so far.
Looking for your advice!

[slotbot]

is it the whammy 4? i remember reading in the manual that there is away to calibrate it. i think you hold down the button while you plug it in, sweep the treadle from back to front then release the button. somethign like that. look up the manual on the digitech website.

the whammy works with an ldr not a pot, as you noticed.

[jrc4558]

Cool! Will try!

[tungngruv]

Unplug the power, then hold down the effect button down while powering it up. One of the lights will flash, then move the treadle all the way forward and backward two times. That will re calibrate the pedal.

[jrc4558]

Thanks guys! I tried as is recommended on their website (they mention only to sweep the pedal trough its range, w/o specifying two times) and it didn't work.
Tomorrow I will try what tungngruv is suggecting. Hopefully...
Thanks for the input!

[jrc4558]

No effect, gentlemen... I tried resetting it about 10 times, no changes in sweep. I'm completely out of ideas at this point...

[Theo]

I have both the reissue and the old one..

On the old one you just move the pedal forth and back a few times to calibrate whenever you turn it on,

but on the reissue you have to hold down the switch when you turn the power on to put the pedal in calibration mode..

the LED should flash

Try it

Theo