Hello.
here is a message to share my experience in solving a problem that appeared on the home-cinema amplifier ONKYO tx-DS494.
In order to sell this amplifier I had to check if all the outputs and all the functions works properly.
On the back of this amplifier you have to frontal output : A and B.
I connect a pair of speaker on A output : no problem. I can adjust volume.
when i connect the pair to the b output and turn the volume knob no sound came out of the speakers until I reach a level defined by I don't know what. :hmmm: My volume level goes from 0 to 80db ( if I remember well ). from 0 to 23 db no sound and when I reach 24 dn sound increase and stabilize.
With hearphone connected, i don' have this problem so I conculde that amplifing transistor could not be incriminated.
I checked on the service manual and saw that there are two or three component that could be the source of the problem : the main processor, some capacitors on the output PCB and relays.
I began testing capacitors: no pb. then I thought that if cannot be the main proc because it ( I think ) works in a binary mode: it works or it doesn't. so I decided to switch between themselves the two relay and :super: : it works. The relays was in fault and did not switches properly.
here is my experience in repairing an amplifier
I have a Onkyo DX-7333 CD player, which sometimes doesn't recognize CDs.
I don't think it's a laser pickup (KSS-213C) problem, because when it recognizes the CD, it plays it without a problem, even very scratched ones.
The next thing is, it should play CD-RWs, but it doesn't even recognize them.
I think it needs adjustment
There are two pots on the main PCB - Focus Gain R123 and Focus Offset R112.
Also there are two test points:
TP1 4 pins, first pair labelled Tracking Gain, second pair Focus Gain
TP2 2 pins labelled RF Out and VC
But in the service manual is no description, what should be measured on the test points and how to set Focus Gain and Focus Offset.
In the attachment is a cut out from the schematic, where the test points and adjustment pots are.
Please if someone knows, how to?
Üdv' Mindenkinek. Kezelőn stby 5V megvan, stby gombon is. A relét, mi bekapcsolja a cuccot egy tranzisztor kapcsolná, aminek a bázisa valahonnan arról a digitális förmedvény panelról jön, ami a mindenféle av és egyéb dolgokat is kapcsolgatja. Ha a relé meghúz, villanyok megjönnek, de továbbra is agyhalott. Itt feladtam.
A cucc pesti.
Ha akad, ki elmolyolna vele, küldjön privátban egy telefonszámot és összehozom a gazdival.
Sziasztok! A segítségeteket szeretném kérni a fent nevezett erősítővel kapcsolatban. Minden működik rajta, de nem jön ki belőle semmi hang. Az egyik ismerősöm hozta, hogy nézzem meg neki, ugyanis a felesége mindig letakarja a szellőző nyílását a tetején egy terítővel mondván biztosan leégett a végfoka. A végfokait megmértem mind jó. Mi lehet a baja? És nem igazán akar működni rajta a hangerő gomb sem (sokszori körbetekerés után 1-et változik) a távirányítóval tökéletesen működik.