Adott egy ilyen hifi, és nagggyon' halvány a kijelzője. Letöltöttem a rajzot, a VKK vonalon mind az 4db C92x+C930 kondit cseréltem, annak ellenére, hogy a feszültségek mindenhol (elvileg megvannak). A fűtésen -20V DC 3.6V AC van. A VKK-n megvan a -27V DC. Most átmenetileg kiszedtem a kijelző elöl egy sötétítő filtert bigyót (a robbantott ábrán a 260-as), egy fokkal jobb lett, de nappal még mindig nem az igazi kijelző.
Valami ötlet mi okozhat még ilyen hibát?
Original problem is no sub woofer output. Been through this one and recapped it and the common 2 burned 1K (R16/17)
resistors are replaced but the sub is still not responding. Volume control potentiometer is a common issue on these but
the L-R spkrs sound good.
Went by this webpage on the repair:
https://christopherbradshaw.net/The_Project_Bin/klipsch%20promedia%20subwoofer%20repair%20-%20page%201.html
On the schematic there is a sub-relay (sw101) powered by +V_HF line it
maybe is suppose to be +V_LF ? Without the relay coming on looks like the sub is disconnected.
The zeners (D03/04) that give +/- Vcc to the op amps seemed way off so I replaced them and the voltages seem much closer.
Theres also a sub-mute line on p104 to p101. Power supply shows the LF mute relay and interconnect diagram says it
gets fed from the LF amp. What is triggering the mute? I dont see a mute button anyplace.