Tiszteletem a Tanyalakóknak!
Szeretnék segítséget kérni Fent nevezett erősítő javításához.
A jelenség: ha a pótméterrel növelni akarom a hangerőt, akkor a 1/3-d fölé érve elnémul, és csak ha kikapcsolom, a potit kicsit lejjebb állítom, és visszakapcsolás után jön vissza a hang.
Az 5. képen látható R803-as ellenállást én tettem bele, mert az elődje, enyhén szólva megpirult. Ez is melegszik nagyon.
Jó lenne valami rajz, hogy tudjak molyolni benne.
Minden segítséget előre is köszönök
Üdv Mekmuki
Buongiorno. L'amplificatore come da titolo inserendo un segnale dai rispettivi ingressi in uscita non si sente nessun suono. Le tensioni allo stadio finale, servite da transistori sono corrette. ho notato che anche nella cuffia non si sente l'audio. Potreste per favore darmi qualche suggerimento in merito? Grazie.
I have and found most of the voltages as indicated on the circuit diagram, till op amp M 5218P; are near those specifed. The output on the centre of the two power transistors of both the channels are also alright.
While looking at the voltages on test points as mentioned on the page 7 for setting up quiscent current, these cannot be set.
Bit of history, the amplifier was lying unused for long time. Nothing in it has burnt. It was never opened earlier than this time, couple of days back.
While I was probing for voltages with DMM, with probe on collector of TR413 one of the fuses blew up. Later same thing happened on the other channel as well.
With the above as background can a Good Samaritan figure out feasibility of repair.
i am unable to upload service manual as file size is 7.3 mb
Hiya, am seeking a Penta amplifier circuit diagram. I have found a few on the web but this request relates to the input board. Early Penta Mark1s used an input board numbered 8002831 and used 6 transistors. my board is numbered 8002831E and looks similar - but in addition to TR1 to TR6 I have TR8 Tr9 TR10 TR16 TR16 on the circuit board. As its this board that is not working i'm quite keen to get hold of the right circuit diagram. The case says Penta 6602. Any help greatly appreciated. Happy New Year