Broken Whammy DT

[fxwiegand]

I just got a DigiTech Whammy that is not working. Just plugged it in and I am only getting the dry signal through, no LED turns on, none of the switches seem to do anything. I don't really have a place to start so if anyone has a good idea where to start I'd appreciate anything you've got. I also noticed that some spots for IC's and resistors seem to be empty (see photo). I only measured the voltage of the power supply which was around 8.7 or 8.3 V if I remember correctly. I didn't measure the current (not really sure where I should). Maybe there is just not enough current since it consumes quite a lot whit its 1300mA. Although it seems to be the original power supply so I doubt that the problem is there.

 

[music6000]

You are using an 9v AC Power supply, Not DC Correct ?

 

[fxwiegand]

The Enclosure says 9V DC:
This is the PS: Sorry for the bad picture, bad lighting.

 

[music6000]

Good, 9V DC is correct, The Whammy needs around 250ma to power up & work, 1300ma is just there to make sure there is an efficient supply in reserve!
Polarity is the next thing that needs to be correct & from the Pictures provided, that is also Correct.
The next place to look would be the Power jack on the PCB board.
Check to see if the Solder pads are good, they are prone to Crack (Dry Joint) being mounted directly to the PCB.
If you are good with a Solder Iron, reflow them just to make sure!
Next would be the Footswitch solder pads, Check for any suspect joints as suggested as per power jack pads.

 

[fxwiegand]

All solder points of the DC In and Footswitches look good. I also measured the connections of the DC In and those seem to be fine. All (momentary) foot switches also work as I can tell by measuring. The jacks should also be fine since my dry signal is getting through right?

Also I noticed that one of the 1000uF capacitors has that weird red marking. Is that something I should be worried about? I sadly don't have another 1000uF on hand, the highest value I have got here is 220uF.

 

[Devoureddeth]

These are notorious for breaking. I managed to fix mine by replacing the capcitor in the psoc reset circuit. Don't ask me why it fixed it but others have found similar it to be a similar fix. http://falseelectronics.blogspot.com/2016/08/digitech-whammy-4.html?m=1

 

[music6000]

This is where you hit a Brick Wall.
All the critical area's have been checked for it to Power Up.
With all the SMD & DSP involved, this is about as far as I can help you.
Are you getting Sound if you unplug the power jack from the Board.
I was about to say these are prone to Fail when Devoureddeth just posted above.
Good Luck!

 

[fxwiegand]

These are notorious for breaking. I managed to fix mine by replacing the capcitor in the psoc reset circuit. Don't ask me why it fixed it but others have found similar it to be a similar fix. http://falseelectronics.blogspot.com/2016/08/digitech-whammy-4.html?m=1

Do you know what capacitor that would be on my board?

Yeah I also get sound from the board when the power jack is unplugged.

 

[Devoureddeth]

It should be C52, there is a schematic on the blog page. The issues with this unit seem to stem from the switching system. C52 is part of the reset circuit for the switching system. I don't know what it is about these switching systems but I encountered a similar system in a Peavy Butcher MKII which required replacement of the capcitor in the psoc circuit.

 

[fxwiegand]

Yeah the problem is that the board there is a Whammy, not a Whammy DT like mine, I should have written that in the thread title. C52 is just a basic SMD Cap on my board.