i've built this pedal a couple of months ago (it's Okko Dominator; it requires 18v supply, so there is a dedicated charge pump), and it was (almost) perfectly working
(https://s22.postimg.org/bbk45nnkx/okko_charge_pump.png)
i've used it several times (before boxing it), then i boxed it and it magically stopped working
i guessed it was a supply problem because there was complete silence, and so it was: today i debugged it, and discovered that there was no 15v output (on the cortrary 18v normally works)...i disconnected the effect, and still there was no 15v on the charge pump...when i plug the adaptor (i tried 2 adaptors and battery too), it gives a lot of shorts (one of them, just for example, it's signed in blue in the second picture), but when the power is not plugged, there is no shorts at all (i checked 10 times about shorts, bridges, that every contact works etc etc tec)
i removed the 7660 IC, and still there's the problem...the 78L15 was burned (i'm sure of it, i tested it, no more 15v from the output), so i tried to replace it (i had some 78M15), but still didnt work (15v doesnt flow, it's always shorted, 0.0v there)...
another strange thing is that every regolator i put on (78M15, or i tried just to see a 78L12 or 78L06) IMMEDIATELY begins to burn, after 5 seconds you cant touch with naked hands (a consequence of shorting, i presume??)
so, tomorrow i'll buy a new 78L15, but im afraid that it will fry too, and the problem will remain...what could it be? i ran out of ideas..could it be one of the 2 diodes??
(https://s9.postimg.org/ckyv88lbz/okko_charge_pump2.png)
Do you have a schematic of the circuit?
You'll get more help if we don't have to reverse engineer the perf board.
The overheating of the regulator indicates excessive current draw. Measure resistance between regulator output and ground. It should be infinite when there is no load on the supply.
QuoteThe overheating of the regulator indicates excessive current draw. Measure resistance between regulator output and ground. It should be infinite when there is no load on the supply.
with regulator mounted on board?
QuoteDo you have a schematic of the circuit?
You'll get more help if we don't have to reverse engineer the perf board.
pardonne moi! :icon_redface:
here's the schematic (i'm not 100% dure it's everything the same because i've taken it from another site than the layout, but it should be)
(http://3.bp.blogspot.com/-y5avWD9qTAI/Tx1seOvAZZI/AAAAAAAAAsg/OGRYy8EMoHM/s1600/OKKO+DOMINATOR+cir+%25281%2529.JPG)
Is this the circuit you are working on?
(http://3.bp.blogspot.com/-y5avWD9qTAI/Tx1seOvAZZI/AAAAAAAAAsg/OGRYy8EMoHM/s1600/OKKO+DOMINATOR+cir+%25281%2529.JPG)
Edit-
Why does your layout only have 2 diodes? (D1 & D2). D3 appears to be missing.
Is Pin 5 supposed to be grounded?
(https://s22.postimg.org/bbk45nnkx/okko_charge_pump.png)
F**K ME!!!!!!!!
i guess i've found the problem...all to me :-[ :-[ :-[ :-[
i've created a line to to star grounding, and add a jumper from ground line but....
instead of putting it here:
(https://s17.postimg.org/xq24660hb/okko_charge_pump4.png)
i put it there:
(https://s3.postimg.org/af4uz4ryb/okko_charge_pump5.png)
sorry for the lost of time, guys... :-[ :icon_redface: :icon_sad:
QuoteIs this the circuit you are working on?
i didnt work with the schematic, i've worked on the layout here:
http://tagboardeffects.blogspot.it/2014/07/okko-dominator.html
and the circuit works good, apart that with 2 BF245 it sounds like messy fuzz, replacing one of BFs with another (like J201 for example) it works like it should (expect there is a little loss of gain)..i don't understand why, but it's good anyway, it has all the gain i need even with J201