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Blown Boss DD3 - help!
So a while back at a time when I was less wise on electronics I got my hands on a Boss DD3 delay pedal, and stupidly plugged it into an incorrect power supply (positive polarity I believe). I've just started the task of fixing this pedal but have run into some problems.
First of all, I cannot seem to trace the +9V supply to anywhere on the board, it seems as if the line from the DC board to the main board (wire 2) is completely dead, so I'm wondering if maybe the transformer (at least thats what I think it is, it looks like an inductor joined with a capacitor on the schematic) on the DC board is bust. I can pick up 9V across the DC input socket and from wire 3 to one of the jacks, but not to the board itself. I'm really confused here unless theres some differences between this model and the schematic I've been referencing (http://www.hobby-hour.com/electronic...-schematic.gif)
I can clearly see that D6 on the board has blown and tried replacing it with a standard signal diode. Whilst this meant that the LED then turned on with the switch, there was no delay output (just a clean signal). I then realised that D6 is actually a zener diode, so have ordered an 11V replacement. I also believe that IC10 (5V reference) may be the problem as it is in close proximity to the diode and would be the reason for the lack of 5V reference voltage for IC7 and hence no delayed signal. Weirdly it now seems that I cannot actually trace any signal on the board after removing the incorrect diode, so am starting to think that the board is possibly gone beyond repair. Any pointers in the right direction would be greatly appreciated!
First of all, I cannot seem to trace the +9V supply to anywhere on the board, it seems as if the line from the DC board to the main board (wire 2) is completely dead, so I'm wondering if maybe the transformer (at least thats what I think it is, it looks like an inductor joined with a capacitor on the schematic) on the DC board is bust. I can pick up 9V across the DC input socket and from wire 3 to one of the jacks, but not to the board itself. I'm really confused here unless theres some differences between this model and the schematic I've been referencing (http://www.hobby-hour.com/electronic...-schematic.gif)
I can clearly see that D6 on the board has blown and tried replacing it with a standard signal diode. Whilst this meant that the LED then turned on with the switch, there was no delay output (just a clean signal). I then realised that D6 is actually a zener diode, so have ordered an 11V replacement. I also believe that IC10 (5V reference) may be the problem as it is in close proximity to the diode and would be the reason for the lack of 5V reference voltage for IC7 and hence no delayed signal. Weirdly it now seems that I cannot actually trace any signal on the board after removing the incorrect diode, so am starting to think that the board is possibly gone beyond repair. Any pointers in the right direction would be greatly appreciated!
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