Siel DK70 Not powering up-- anyone have a service manual?
2010-09-24 by Mark
I was wondering if any of you had a schematic or a service manual of this synth. When I switch the keyboard on, I hear a faint click in the psu section, but the keyboard does not power up. There are four test points conveniently located near the psu board to test voltage. I've hooked them up to a oscilloscope and they are reading the proper voltages (+12, 0V, +5 and -12). Siel was very helpful in the development of this synth, they labeled the proper voltages here on the pcb. However, when I try the test points to the right of the circuit board, I get no voltage readings at all. There are no voltages listed on the pcb in this section. These test points are near the BBD chip and the DAC. There is no power on the cpu board at all. I replaced the two larger caps near the power input but not any of the other electros. There are no visible signs of damage to the pcb at all or any components. What I hate to think about is that it could be a stupid diode or a regulator somewhere that is dead. I'd really like to get this thing powered up, lol.