Tweet
Hi
This one has come to me with a group of studio stuff and is the last one that need repair
The reported fault was no 48v phantom . Found a few blown caps that had been changed before. Changed them and tested 48v up to 60v.
When i checked everything out i can see that loads of stuff been changed before
18v +/- regs had been swapped for 15v +/-
I also found 2 short zeners diodes and a cap in wrong way round
I have no schematic for this unit.
who ever has changed these parts has swapped IC9 which has the supply for the 48v
They have fitted a KA7815. and tried to mod the circuit
The switch on the front panel turns on a transistor that grounds the centre pin for whatever was in IC9
When i fit a test reg in the same place as IC9 whatever i fit ie 12v - 15v works perfectly
when i switch on the phantom is whatever the reg is supposed to be
does anyone have any ideas on what ic9 should be
This one has come to me with a group of studio stuff and is the last one that need repair
The reported fault was no 48v phantom . Found a few blown caps that had been changed before. Changed them and tested 48v up to 60v.
When i checked everything out i can see that loads of stuff been changed before
18v +/- regs had been swapped for 15v +/-
I also found 2 short zeners diodes and a cap in wrong way round
I have no schematic for this unit.
who ever has changed these parts has swapped IC9 which has the supply for the 48v
They have fitted a KA7815. and tried to mod the circuit
The switch on the front panel turns on a transistor that grounds the centre pin for whatever was in IC9
When i fit a test reg in the same place as IC9 whatever i fit ie 12v - 15v works perfectly
when i switch on the phantom is whatever the reg is supposed to be
does anyone have any ideas on what ic9 should be