Sansui 9090
 

Hello All;
I have a Sansui 9090 since I bought it new. Other then a few small
problems with it over the 30+ years I have own and operated it has been a
great receiver. Reciently I was playing tunes, when suddenly the receiver
quit playing. It was still powered up, and when I checked it out the switch
warning was, and is flashing red constantly, when it should change to green
after first turning on. It is an overload protection switch, and it won't
change to it's normal green when all systems are go color. In the past if I
were to drive it to hard, it would do the same, but after adjusting volume
and bass down, it would be fine again.now it stays in this flashing red
mode, and will not clear and turn solid green as it should.
Has any one any ideas on this one. Thank You

Sansui 9090
 

GD wrote:
Hello All;
I have a Sansui 9090 since I bought it new. Other then a few small
problems with it over the 30+ years I have own and operated it has been a
great receiver. Reciently I was playing tunes, when suddenly the receiver
quit playing. It was still powered up, and when I checked it out the switch
warning was, and is flashing red constantly, when it should change to green
after first turning on. It is an overload protection switch, and it won't
change to it's normal green when all systems are go color. In the past if I
were to drive it to hard, it would do the same, but after adjusting volume
and bass down, it would be fine again.now it stays in this flashing red
mode, and will not clear and turn solid green as it should.
Has any one any ideas on this one. Thank You


GD,

Unfortunately, you most likely have an output stage failure, and the
'Protector' is preventing speaker damage. The first thing I'd would do
as a service tech is to look for DC offset on each of the channels
before the speaker relay. **IF** there is DC there, you need to repair
the channel that has the DC offset. If both channels have the same
offset, then I might look at power supplies first. Note that DC of + or
- 50mV is acceptable and not likely to be a fault. This test is made
with nothing hooked up to the receiver, and the volume control all the
way down. You could also check for internal fuses, I forget if the 9090
has them or not.

Regards,
Tim Schwartz
Bristol Electronics

P.S. If you've never worked on a amp/receiver before I'd suggest
getting it to a servicer, or call in a friend who has.

Sansui 9090
 

GD wrote:
Hello All;
I have a Sansui 9090 since I bought it new. Other then a few small
problems with it over the 30+ years I have own and operated it has
been a great receiver. Reciently I was playing tunes, when suddenly
the receiver quit playing. It was still powered up, and when I
checked it out the switch warning was, and is flashing red
constantly, when it should change to green after first turning on. It
is an overload protection switch, and it won't change to it's normal
green when all systems are go color. In the past if I were to drive
it to hard, it would do the same, but after adjusting volume and bass
down, it would be fine again.now it stays in this flashing red mode,
and will not clear and turn solid green as it should. Has any one
any ideas on this one. Thank You

Pretty unlikely to be a doit-yourself type of repair. Either a blown amp
channel or regulated power supply problems - that's where I'd start
anyway...

Mark Z.