Hello Mishraji,
Can you please explain in detail your above line with some sketch.
Sadik
I can't draw sketch now. But let me explain what and why I mentioned that.
Take any rectifier board above:
- It has 2 bridge blocks made from 4 dual diodes each (total 8).
- There are (from top-bottom) 4 wires from 2 secondaries of same transformer, we name 4 wires as (S1a, S1b) and (S2a, S2b)
--S1a--
--S1b--
and
--S2a--
--S2b--
What I meant was take any one rectifier board,
1. Try to exchange wires positions S1a<->S1b and/or S2a<->S2b
2. If 1 does not solve your problems then exchange Wires of S1*<->S2*
Why - because there is only one transformer not two. So When +/- are derived from bridges they come from same source but different diodes. Hence getting '0' by connecting one bridge '+' and another bridge '-' makes ground with common noise. It may peak or cancel itself depending upon phase of noise. With reference to another board's 0, this 0 might be at slightly different level. Somehow by trial and error method of wire connections, we can try to make the difference minimum.
But here single ground isolator (rather connecting both '0' at ground isolator with long wires) is introducing big ground loop -
from one PS '0' -> amp board -> input RCA -> Source-> Another input RCA->Another amp board -> another PS '0'-> ground isolator -> first '0'. Disconnecting this loop at input RCA stops noise which is amplified from input ground current of loop.
Rather he could have removed one '0'-> Ground isolator wire.
But somehow he fiddled with running amplifier to enter into repair mode which is more challenging because I afraid he may need those difficult to get Toshiba input JFETs too.
