aw man, killed my GGG PT-80!!

[runmikeyrun]

so, there was this moment of stupidity yesterday when i switched my power supplies on two of my pedals.  My 12v Budda got 24v, and my 24v PT-80 got 12v.  The budda is already off to the repair shop because i smoked the tranny on it.  I built the PT-80 kit off GGG and it was basically a paint by numbers.  I don't know the theory of BBD devices so i'm not sure where to start to debug this thing.  I'm getting signal through the unit when the effect is on, i am just not getting any delay.  The controls aren't working, even the volume.  Nothing on the board looks smoked, burnt, or smells funny.  I believe there is a protective diode on the circuit so i can't see how running it at a lower voltage could have done anything!

I will post voltages soon... in the meantime, any random guesses will be accepted!

Thanks in advance.

Mike

http://www.generalguitargadgets.com/diagrams/pt80schem.pdf

[geertjacobs]

Eh, there's no bbd in a PT-80 if I'm correct. It's a one-chip digital delay IC.
First things I would check is whether the 7805 and the 7812 voltages regulators are still alive.
If they are and you get no sound, you may have to get a new PT2399 delay IC.

I'm going to have the same problem if I don't watch out, I run my PT-80 from a 15V unregulated adapter (more like 18V).
I read somewhere that if you use different voltage/polarity adapters, you'd better use different sizes/shapes of plugs for each polarity/voltage.
Seems like a good suggestion...

[Marcos - Munky]

Strange, never heard about an something that blew because of use of a voltage lower than necessary. The only effects I heard blew because of power supply was because of higher voltages (for example, your wah).

[runmikeyrun]

ah, sorry,  my mistake.  I thought it was a bbd.  I have signal through it when the effect is on, just no delay.  There is no degradation or loss of volume, it sounds exactly the same as the bypassed signal. 

[RDV]

A random guess would be a problem around the PT chip, probably a cold solder joint on a cap or something.
IMO low power won't hurt it.
Check your voltages off the regulators though and post them.

RDV