Hi Everyone,

Recently I bought a fulltone fulldrive. In the manual it says that you can give it up to 18V so i wanted to test this.
Yesterday I got a professional power supply capable of delivering up to 20V. (elektro-automatik www.elektroautomatik.com)
I set it to 9V and hooked it up to the pedal. It didn't work and my pedal doesn't work at all anymore. Something got fried in there as I could smell a burning air. I have no idea what I've done wrong.
I'm thinking it might have something to do with the ampere. The machine is capable of 2A. I don't know if it actually sent 2A thru the pedal. Do you guys have any ideas ?

I'm new at this so if you need more info let me know.

Greets,
Ivo

If the limit is 18V and you fed it 20V you've probably fried something.  I don't know anything about this circuit, but if it uses ICs post the codes and people here will tell you if you've gone over the ratings.

I am certain that I didn't put 20V on the pedal. The max i used was 9V just like a regular adapter. After that everything was dead. The only thing working is the true bypass. But as soon as the circuit is activated there's no more guitar signal coming thru. So something else must have gone wrong besides the voltage. I'm thinking ampere.

Anyone ?

Ivo

More than likely you've fed the poor thing reverse polarity. I'm not very familiar with FT's stuff, but it should have diode protection against just such a thing. Open it up and trace the power wire from the power jack back to the board, there you should find a fried diode like a 1N4001 or a zener diode of some sort. It should be easy enough to find. It'll stink. Replace it and your pedal should work again.

HTH

RDV

Didn't read your post properly, sorry!  If your supply is the wrong polarity don't plug it in to your effect anymore.  If you have fried the protection diode then that protection is lost, so you might damage your effect (if you haven't done so already) if you plug your supply in again.

It should say on the adapter somewhere what the polarity is, and should say somewhere on the effect/in the manual what polarity you should use.

Hmm so the reverse polarity could actually have caused the damage ? I've got i wrong before on other devices and they didn't seem te mind..but you are right about it being the first thing that is connected to the board from the power supply. I think the diode is fried and maybe the capacitator too ?
I'm not able to repair this myself as the board is glued to the frame. And i don't think warranty covers this. So basicaly i'm f*****d.

Any ideas?

ivo

Does it work with a battery in?  If not, then it's probably been damaged.

Form the top of the board?
 Every time I did a Friode, it was visibly damged looking to a great extent, possibly you can smash/cut what's left of the diode glass off of the lead, [ckt side, check [pin8?] continuity between the diode and the OA's Psupply pin]
the tack a wire from there [what's left of the diode lead to ckt] to the battery or install a new diode in the new line.

I've done my share of reverse-polarity screwups :mrgreen: The center pin of a DC plug is negative with FX building. Don't ask me why it just is

Is there a way you can post a picture of the board on-line?

One of two things has happened. (1) There may be a protection diode across the power input has become shorted, or (2) other components have failed. If the problem is #1, the repair is very simple.

Good luck,
-Peter

okay i've made a picture of the board. It's not very clear but I think it'll do..i've marked the position where the diode is.
As you can see i cannot see the wiring of the board since it's on the other side and it's glued to the body. It seems that most burn marks are under the blue capacitor next to the diode.

Let me know what you see.

http://home.planet.nl/~verberk/board.jpg

Ivo

It's difficult to tell without seeing the traces, but I'd guess that the diode is connected up across the rails and has fried.  If you test the diode with a meter you'll know if its open.  It's also possible that the cap has been damaged if it's polarised (does it have a negative symbol written on its case?) and is connected up across the rails too.

Stick a battery in.  If nothing has been damaged except the protection diode and filter cap (?), then the circuit should still work.

PS  If it's new it might be worth complaining.  If it's supposed to be protected against accidental reverse supply then it should survive such scrapes!

As Gez said, it's difficult without seeing the traces, but it looks quite promising.

If you have a meter with a diode test function, try measuring across the diode. My guess is that you will see a short circuit. If this is the case, you can just break the diode with pliars and the pedal should start working again. Just be extra careful, because now there is no protection.

A 9V battery will not produce enough current to kill a 1 amp diode, but a 2 amp supply will.

Good luck,
-Peter

I tested the diode. It is still okay. So something else is malfunctioning. Anyone here know what it can be ?

Ivo

Quote from: smoguzbenjaminI've done my share of reverse-polarity screwups :mrgreen: The center pin of a DC plug is negative with FX building. Don't ask me why it just is

I`m not sure, if this should be said so generalized...

QuoteThe center pin of a DC plug is negative with FX building. Don't ask me why it just is

I *think*:
1) it's a good idea to switch the battery in and out at the ground connection (otherwise there's a whole circuit in between, and the inserted powersupply jack can give the battery a nice, albeit short, wallop to cause it to leak and nasties like that). The pin also connects first on a lot of jacks.
2) Most if not all DC jacks only switch the pin, not the sleeve.

Once again, I think so, but am not 100% sure

Did you buy this effect new or secondhand?  Clutching at straws here, but if it's secondhand and reasonably old maybe that electrolytic has gone bad with age?

Was your adapter the wrong polarity?  If it's right it may have been shorted by a failing component?  That cap?  Check with a volt meter to see it the adapter is still churning out 9V (might not be short circuit protected).

Just guessing with all the above...probably rubbish!