Hi, I got this Alpine CVA-1005 for repair which has been to a couple of technicians before me , all who've given up on it. Symptom , no signs of life though it seems to draw 0.35 amps from my ps ) I open the hide away unit and while tracing supply and acc lines ( i don't have a service manual) i reach the first power switching transistor , a
2SB1417 ( Q 8027 on the pcb ). I notice that someone has messed around in this region. Strange thing is, the base lead of the transistor , doesn't seem to be going anywhere , apart from to the 1.5 K ohm resistor tied to supply and the emitter of the transistor. Obviously the base would have to be connected to some device that would pull it low , when on, for the transistor to be forward biased. I pulled out the transistor and examined the copper trace and, zilch , no connection whatsoever. So my guess is there's a wire missing and i need to know between where and what. If someone has the service manual or a working piece, i'd be greatly obliged if they could look this up and inform me. Emitter 12v (+B) Collector 0v (output switched dc) Base 12v (control) I don't think buying a service manual would be a good idea as i rarely get these units. Thanx in advance, Jango. crow snipped-for-privacy@yahoo.co.uk- posted
18 years ago