Does anyone have a service manual for a QX4000 receiver?
When I got it out of my Dad's attic it was really scratchy. I got zero music out of the speakers - just static. From the headphone amp I could hear a little music signal, but the static was still there and still bad.
First thing I did was clean all of the pots, but that wasn't it. I tested the power transistors, and one of the eight had different voltage on the center pin. I replaced four of the eight transistors (one entire bank, I'm assuming 4 transistors for two of the channels).
No luck... but a change. Now instead of static, I get nothing at all. No static, no pop from the speakers when I power it on, nothing from the headphone jack, nothing at all.
The receiver still locks onto stations and shows good power, so that part is still working, but something in the amplifier circuit is hosed, and I have no idea where to start. I'm a newb when it comes to electronics. I know how to solder and just enough to be dangerous, but I have no idea what any of the boards inside do.
Charles
When I got it out of my Dad's attic it was really scratchy. I got zero music out of the speakers - just static. From the headphone amp I could hear a little music signal, but the static was still there and still bad.
First thing I did was clean all of the pots, but that wasn't it. I tested the power transistors, and one of the eight had different voltage on the center pin. I replaced four of the eight transistors (one entire bank, I'm assuming 4 transistors for two of the channels).
No luck... but a change. Now instead of static, I get nothing at all. No static, no pop from the speakers when I power it on, nothing from the headphone jack, nothing at all.
The receiver still locks onto stations and shows good power, so that part is still working, but something in the amplifier circuit is hosed, and I have no idea where to start. I'm a newb when it comes to electronics. I know how to solder and just enough to be dangerous, but I have no idea what any of the boards inside do.
Charles
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