Hi All,
I've got a dead Pioneer VSX-818V Receiver, its completely dead, no lights, doesn't do anything.
Checking out the power supply (pic and schematic below), it has a standby circuit which provides 5v from a small transformer/rectifier and regulator setup, which works fine, I can read 5v wherever the standby voltage is on all ICs, connectors and boards. The main transformer is switched in via a relay on the power board after its switching transistor receives about 5v from the "relay enable" pin on the main IC. I've applied 5v to the transistor and conform the relay works, and all "normal state" voltages also are ok once the relay kicks in.
The problem appears to be the main IC never produces the signal to enable the relay.
Checking out the main IC, I can read 5v and the two standby voltage pins, nothing (0v) at Vcc which I assume is expected as its not yet turned on, grounds are OK, nothing at the various clocks and oscillators. Part # PEG467A8 (nothing turns up online).
This is where I'm stuck, I assume from here that the IC (PEG467A8) is dead and I'm not going to replace it, but before I trash the whole machine I thought I'd ask if anyone might know of something else I could do here to work out the issue, or maybe this IC is just dead?
I also tried tracing the power button down to the main IC and see if I can activate the line and see what happens, but the power button goes in to another IC, the display IC (part# PE5550, which I cant find online), and there isn't any obvious "power on" lines from that IC to the main IC, I suspect maybe its some data being sent because it has a few data lines between them.
Thanks for reading this and if you have ideas please comment.
I've attached pictures of the various diagrams:
1. power-board-annotated.jpg - power relay board with key components identified.
2. main-logic-annotated.jpg - Main board showing the main IC that provides "relay enable" 5v to the power relay.
3. image4.jpg - Main IC (PEG467A8) schematic.
4. image5.jpg - Relay power board schematic.
Any help will be greatly appreciated.
Thanks,
Synth-Dude