EII Power supply problem, ( hiccups )
2008-02-28 by synth.junkie
Can anyone help with a psu fault or have you experienced the same fault? The psu in my eII is hicupping, All the voltages are present on the outputs except for the 12 volt rail which is shorting to groud via the SCR turning on, therefore causing the PSU to hicup. I have replaced the scr and zener diode connected to it. I have changed all elect caps in the secondary and primary circuits. I have checked all resistors on the board and they are in tolerance. Diodes and transistors seems fine? Adjusting the 5v rail pot on the secondary does not change the 5v output voltage but it changes the speed of the hicupping that is heard? By removing the scr out of the circuit on the 12v rail, this allows all voltages to be up and now stable, but the voltages seems too high in the secondary, the 5v rail goes up to 8 volts and the input side of the regulators on the -15 and 13.4 volt rail are at about -27 and +27 volts. Can anyone help thanks