Hi all – I am trying to troubleshoot and repair a Bryston BDP-1 network streamer. This system is a bit long in the tooth, but it has served me well and I am hoping someone may help me identify where the failure is occurring.
What I’ve determined so far is that the BDP-1 is failing to boot properly due to a failed serial connection between the main board (a PC Engines Alix 1D augmented by an ESI Juli@) and the Bryston manufactured front panel board. The front panel board controls the PSU, and it is connected to the main board by a 10 pin IDC ribbon cable. If the front panel board does not receive a serial signal from the main board via that ribbon cable within two minutes, it throws an error and cuts off power to the main board.
So far I have tried multiple replacement IDC ribbon cables to confirm it isn't a cable issue, and I have replaced the battery inside the Alix board (which I understand from Bryston can also cause this error).
I have been able to confirm so far that the main board is booting the Linux image correctly, but I cannot tell where in the chain the serial failure is occurring. Basically, if I can determine that the serial bus in the main board has failed, I’m fairly confident I can source and install a suitable replacement Alix board. If the failure is on the Bryston board, then I’ll likely need to pursue a manufacturer repair.
Thankfully, because the BDP-1 is so old, Bryston has shared the schematic (which includes everything except the commercially available Alix/Juli@).
Can anyone share any ways I can troubleshoot the serial ports?
I have a USB to TTL cable, but when I open a serial terminal in Windows I’m not able to observe any behavior in either the Alix or the Bryston boards. I’ve read extensively on loopback tests, but I haven’t been able to determine how best to conduct that at the board level on this product. I did successfully loopback the USB to TTL cable and confirmed it’s working correctly.
In addition to the TTL to USB, I have an oscilloscope and multimeters. I just don't know what to look for to confirm signs of life on the serial ports.
Here is the BDP-1 schematic, and here is the Alix 1D manual.
Any thoughts?
Thanks
What I’ve determined so far is that the BDP-1 is failing to boot properly due to a failed serial connection between the main board (a PC Engines Alix 1D augmented by an ESI Juli@) and the Bryston manufactured front panel board. The front panel board controls the PSU, and it is connected to the main board by a 10 pin IDC ribbon cable. If the front panel board does not receive a serial signal from the main board via that ribbon cable within two minutes, it throws an error and cuts off power to the main board.
So far I have tried multiple replacement IDC ribbon cables to confirm it isn't a cable issue, and I have replaced the battery inside the Alix board (which I understand from Bryston can also cause this error).
I have been able to confirm so far that the main board is booting the Linux image correctly, but I cannot tell where in the chain the serial failure is occurring. Basically, if I can determine that the serial bus in the main board has failed, I’m fairly confident I can source and install a suitable replacement Alix board. If the failure is on the Bryston board, then I’ll likely need to pursue a manufacturer repair.
Thankfully, because the BDP-1 is so old, Bryston has shared the schematic (which includes everything except the commercially available Alix/Juli@).
Can anyone share any ways I can troubleshoot the serial ports?
I have a USB to TTL cable, but when I open a serial terminal in Windows I’m not able to observe any behavior in either the Alix or the Bryston boards. I’ve read extensively on loopback tests, but I haven’t been able to determine how best to conduct that at the board level on this product. I did successfully loopback the USB to TTL cable and confirmed it’s working correctly.
In addition to the TTL to USB, I have an oscilloscope and multimeters. I just don't know what to look for to confirm signs of life on the serial ports.
Here is the BDP-1 schematic, and here is the Alix 1D manual.
Any thoughts?
Thanks
The schematic shows the serial port is at RS232 levels (via ICL3232). Your USB-serial adapter uses TTL levels. Have you taken care of this issue?
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