Hello, I got a problem with my Sony Receiver STR-DE 225.
There´s a sudden interruption of Audio in non defined intervalls - may be once ore 6 times during appr. 5hrs operation.
Interruption does not depend on Volume. Connection cables and speakers I´ve checked.
There´s a loud crack in both speakers, display shows for short time "PROTECTION".
After switching off and on again, everything operates normal until next interruption.
I removed from the inside of the receiver a lot of dust with a vacuum cleaner, but this didn´t help.
Unfortunately Sony has no documents for this device, as it is To "old" (1996), or could give me a hint,
in what cases "PROTECTION" might appear.
Is there anyone to give me a clue? Thanks
Sziasztok. Van egy Sony XOD70 nevre hallgato hi-fi tornyom, es bar taviranyithato, nincs hozza taviranyitom. A taviranyito tipusa RML510, de nem talalok sehol elfogadhato aron. Talaltam viszont tobb mas tipust, amelyek nagyon hasonloan neznek ki, csak nincs tapasztalatom az audio szerkentyuk teren, menyire kompatibilisek a kulombozo tipusok. Ha valaki jartas ebben a temaban, kerem segitsen. A kiszemelt taviranyito tipusa RMS271.
Sziasztok!
A SONY MHC-EC55 tipusú hifihez keresem a következő távvezérlőt: SONY RM -SC50.
Űdv.József
Want to share:
Have downloaded the schematics from this forum to help repair the amplifier of a friend.
Turned out that Sony decided to route the earth through the chassis, even the earth between the various supplies.
When one takes the main board out of the chassis and switches the amp on, there are up to 20 volts difference between the eart (and hence reference) of the pre-amps and the main amps.
Luckily the amp goes into protection but from a design point of view it is not nice to rely on screws and aluminum face plates to conduct up to 0.2 amps of current from one supply to another.
What I did is solder wires to every eart point and connected them on the main board to make it stand alone and not rely on conducting current through the chassis anymore.
Bad design, simple repair but took some digging in the schematics to find out what exactly was going on!