Sziasztok !
A fenti hibán hogyan lehetne segíteni zöld színű fűtőszálas kijelző van benne pontosan nem tudom megnevezni a típusát. a fűtő fesz 24volt helyett csak 23 volt ez lehet a gond?
Üdv nektek!
Friends Sony STR DH130 goes into protection mode soon after turning on. It works for a second then can hear loud pops from speakers.
I've tried the suggested methods to fix but nothing works. Correct impedance speakers. Speakers wired correct. Good ventilation.
I've tested the output transistors in circuit and I don't see anything unusual. I may pull them to test but will wait for advice here. I also measure
about 57 volts on the emitter resistors. Seems high to me. Anyone?
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!
Üdvözlök mindenkit!
a fentnevezett cd rádiót nem lehet bekapcsolásra bírni,lemezt kivenni a tápokat nézegettem a 3.3v megvan,a 9v megjelenik ha felteszem az előlapot és már indul is a demo üzemmód mindenféle hasznos információval a kijelzőn, pl: ha nem tudná a gazda elolvasni a szitanyomáson hogy sony, Mp3,tuner........
Ha valaki találkozott már hasonló problémával vagy sikerült megoldania kérem segítsen.
Krisztián