reset DEC840 device

[amastrangelo]

Hello,

I believe I may have bricked my DEC840 device. I inadvertently removed an interface, which has locked me out of the firewall. At the same time, I attempted to connect via the serial cable using the standard parameters (115200, 8, N, 1, N), but I'm not receiving any proper response. Instead, I'm only seeing garbled characters on the serial console.

Could anyone advise on what steps I should take next? Any help or suggestions to recover the firmware would be greatly appreciated.

Thank you in advance for your support.

Best regards,

[meyergru]

Garbled characters on serial connections are often a sign for wrong parameters. I would try other speeds, although 115200 is the one Deciso specifies for their devices. Also, depending on how you connect, some serial chips do not support those non-standard speeds, but only 38400 max.

If you use a serial-to-usb converter, there are those using FTDI chips. Newer FTDI Windows drivers deliberately fail when they detect a fake chip. You can find older drivers for FTDI in archives on the internet. Any Windows update will update the driver again, though.

[amastrangelo]

Do you have any other suggestions? I really don't know what to do.
I'm using the mini USB cable included in the package. Am I doing something wrong?

[cookiemonster]

probably not but the OS plays a part in this as meyergru alluded to. Are you able to work from a linux/macOS machine?
MS windows with those drivers things can be doing the bad deed.

[passeri]

As a non-Windows experience, I found the most trouble-free application was the Unix/Linux Terminal feature screen rather than provided apps even on a Mac. Garbling is almost always failure of communication parameters. Try checking and varying them very carefully :)

[cookiemonster]

I use minicom and works wonderfully. This is why I was asking the OP what OS he has access to.