I have a Pioneer BDP-LX58 which is not booting up/responding to power - the service manual has some generic schematics but no information on boot/power-up sequencing or test points, rather just says to swap main board based on a limited flowchart. I'm looking to repair this board back to working order.
At the moment I'm suspecting firmware corruption or similar. I have a second unit with a board and different fault to compare with, so there's a few things to check.
The 'good' board powers up immediately into standby and waits for power-key signal to wake up and power on.
The faulty board powers up and draws around 450mA from supply, appears the main 'MPEG' device is running (warm but not hot, not shorted), and the '232TX' line is active to the embedded controller handing IR signals/power up key monitoring etc. Power_Key is 3.3v (active low) and when pulled low, nothing happens. There is some activity reading from the NAND flash.
I have been looking for potential backup firmware recovery options such as RS232 console, ethernet, usb etc (as I have seen references to TFTP etc in the firmware file). I could swap the NAND flash between boards but reluctant to do this until a bit further into the diagnosis.
The embedded controller has a 'DEBUG' header on the other side presumably so the factory can reprogram that if needed but not sure that's at fault, however it is odd that it powers up the main controller automatically on powerup where the good board is in standby (<50mA).
Any ideas/pointers welcomed.
Keith